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April-Grow me now Asian Greens

April 2024 Grow Me Now – Asian Greens

A word of caution: (animal manures, compost, vermicast, and soil in general, can pose serious health risks. Learn how to use these garden additives safely before you begin working with them, especially when using them to make liquid manure plant feeds).

Asian Greens – Made for Autumn!
Autumn offers an exciting window of opportunity for growers, and for anyone who didn’t manage to get their soil into shape for spring and summer, it’s the perfect time to develop a tunnel house salad and greens garden. The term ‘Asian greens’ encompasses a wide range of crisp, tasty vegetables that grow rapidly and lend themselves to a quick turnaround crop that can be harvested in time to make way for a later batch of more traditional brassica. Some of the easiest Asian vegetables to grow include mibuna, mizuna (red and coral), tat soi, choi sum (green and purple stemmed), shungiku, a wide range of pak choi, broccoli Chinese gai lan, and red and green mustard. Hearting varieties of Asian greens, such as Chinese cabbage, along with large winter radishes (such as daikon), are prone to running to seed should a warm spell arrive, and are best grown outdoors.

Ground work
Make no mistake about it, Asian greens are wonderful performers, often harvestable in as little as 4 weeks, with many being ‘cut and come again’ vegetables. But, that said, they will quickly run to seed if they are not given first class treatment, and that begins with soil preparation.
Summer edibles have by now spent months in the tunnel house, and by April will have thoroughly depleted the soil you prepared for them back in September. Not only that, but as you have tapered off watering to assist with the ripening of fruit, the ground these plants have relied upon will be open and dry. Remove their spent summer growth, and before you replace them with anything else, water the ground deeply.
Deep watering involves applying a steady, light stream of water to the ground in an unhurried way, or turning on the sprinkler for half an hour or more. You can use a watering can for the job if you have strong arms. As a guide, use no less than 10 litres (two full, average-sized watering cans) of water for every half square meter of ground. Allow the moisture to seep in, then return 30 minutes later to repeat the treatment. Leave the soil overnight, then water once or twice again.
The greatest cause of Asian vegetables running to seed is lack of moisture, so to create an environment that will hold it in, while still being free draining, you will need to apply lashings of humus-rich compost (3-4 household-sized buckets per half square meter is not overdoing it). If your compost does not include aged animal manure, you will also need to scatter some of this onto the tunnel house beds at the rate of 1-2 buckets full per half square metre Once you have assembled your ingredients, fork everything together well, and water deeply one more time.
Next, prepare a concentrated liquid feed by soaking together for a week, in equal quantities, the following: chopped seaweed (seaweed extract can be purchased from the garden centre if you cannot lay hands on kelp), shredded comfrey leaves, and mature compost and/or vermicast. Dilute at a rate of 1 to 4 for use as liquid manure feed.

Sowing and Transplanting
All Asian greens are best grown in-situ, but you can get away with carefully transplanting many varieties (read seed packets for instructions). In general, avoid transplanting mibuna and mizuna to prevent it running to seed, and instead, sow it thickly as you would mesclun mix (aiming to have seeds fall just a few millimetres away from each other). Bearley cover with sieved soil. Sprinkle with water.
Other Asian greens can be transplanted, using a dibber, around a hand’s space apart. These tender greens are easy prey for slugs and snails, so if you are not prepared to pick the beasties off after dark with the help of a torch, scatter low-hazard slug and snail bait around the plants, and keep children and animals well away from the area at all times.

Maintenance
You are aiming to have your Asian greens grow as rapidly as possible. To encourage this, keep the soil damp, but not moist, by watering in the morning so that leaves are dry by nightfall. Where safe to do so, apply liquid feed once a week, ensuring it does not touch the edible parts of any plants. To encourage warmth, but not too much (Asian greens prefer temperatures in the range of 13 to 18°C) open vents and windows during the day and close them up again at night. On warm days, leave the door of the tunnel house open as well, to allow air to circulate, but cover the opening with mesh (or invest in a screen door) to keep out birds and animals. Close again at the end of the day.

Tips:
Harvest greens according to instructions on your seed packets, bearing in mind that is often not necessary to cut off an entire plant at the base. Rather, individual leaves can be harvested, extending the life of the vegetable.

When your greens eventually begin to bolt (run to seed) make use of their pretty flowers by using them in stir fries, salads, rice paper wraps, and dumplings.

Over-mature Asian greens can still be eaten if you are prepared to peel stems. In fact, celtuce (Chinese stem lettuce) is grown specifically for its crunchy thick stem.

When using is salads, go easy on the mustard green (save them for your kim chi and other pickled Asian green recipes).

as soon as they are a suitable

April Grow me now – Celery

April 2024 Grow Me Now – Celery

A word of caution: (animal manures, compost, vermicast, and soil in general, can pose serious health risks. Learn how to use these garden additives safely before you begin working with them, especially when using them to make liquid manure plant feeds).

Super Celery!
Where would be without celery – at any time of the year – but especially over winter. It is an essential ingredient in slow-cooked comfort foods, provides a fresh, tasty crunch to cool season salads, and when stuffed with cheese, becomes a special snack that both children and adults can’t get enough of. Sadly, many tunnel house growers shy away from planting celery because they have had bad experiences with cultivating it in the past. Either it turns out to be bitter and stringy, or it bolts to seed before harvestable. Fortunately, growing celery isn’t at all difficult once you know how. And if, after reading the advice below, you still feel anxious about introducing celery to your undercover beds, we have a couple of alternatives that will tick the boxes (see the ‘tips’ section at the end of this blog).

Seed raising
Celery will perform well, but only on one condition – that you treat it like a king at all times. Just one slip-up, from seed to maturity, is enough to see it perform poorly. When you buy your seedlings from a garden centre or nursery, you don’t have control over the conditions they have been through. They may have been under- or over-watered, or been through very hot or very cold temperatures. All of which will affect the quality of your plants down the track. So, wherever possible, raise the plants from seed which you sow yourself.
To do this, sow seed into a seed-raising tray filled with quality commercial seed-raising mix, and cover it with a bare sprinkle of fine mix. Keep the seed raising mix damp, but not moist, by spraying it with water from a spray bottle. Germination takes place, ideally, when soil temperatures are around 21-25°C, so you may need to place your seed raising tray on a germinating pad if you are sowing at a cooler time of the year.
While you are waiting for the seeds to germinate (they take around 3 weeks to do so), fill single cell seedling punnets with potting mix (single cells makes for less disturbance at transplanting time). Unless you are experienced at making your own potting mix, choose a sterilised commercial brand so that there is less chance of introducing fungal disease to the tiny seedlings, and add to it an extra scattering of slow-release fertiliser pellets to it.
Once the seed have germinated, and the seedlings have developed 3 true leaves (leaves that look like those on an adult plant), it’s time to ‘prick them out.’ To do this, gently tease them out of the seed raising mix, using tweezers, and plant them (1 to each cell) into the seed raising mix. Be sure to plant the seedlings at the same depth they were growing at in the seed raising tray (certainly not any deeper).
Keep the seedlings in a sunny, sheltered spot, taking care not to expose them to temperatures of less than 10°C. If they do encounter cooler temperatures, or if they are allowed to dry out, the adult plants will likely run prematurely to seed once they are in the tunnel house.

Ground work
Come April, summer edibles have already spent months in the tunnel house, and by mid-autumn will have thoroughly depleted the soil you prepared for them back in September. Not only that, but as you have tapered off watering to assist with the ripening of fruit, the ground these plants have relied upon will be open and dry. Remove their spent summer growth, and before you replace them with anything else, water the ground deeply.
Deep watering involves applying a steady, light stream of water to the ground in an unhurried way, or turning on the sprinkler for half an hour or more. You can use a watering can for the job if you have strong arms. As a guide, use no less than 10 litres (two full, average-sized watering cans) of water for every half square meter of ground. Allow the moisture to seep in, then return 30 minutes later to repeat the treatment. Leave the soil overnight, then water once or twice again. You are now ready to add the hefty doses of soil additives that your celery seedling require for fast, unchecked growth.
Dig the tunnel house bed to a depth of a spade’s blade. As you do so, over the space of half a meter, chop in as much mature compost as you can spare (5 or 6 buckets, if possible). Also add 2 buckets of aged animal manure over the same area, a couple of handfuls of blood and bone, and a bucket or two of well-rotted kelp or seaweed.
Celery thrives in soil with a pH level of between 6.5 and 7.5, so, if your tunnel house bed has been set up for tomato plants, it will almost certainly need the addition of lime at a rate of 30-40 grams per square meter. Unfortunately, soil is slow to take up lime, so applying it at the time of planting your celery is unlikely to help. Don’t be concerned, because your celery will live without lime, and your tomatoes will appreciate the same space next spring, without it. Once you have dug all the nutrients into the tunnel house soil, water it twice, as above.
Lastly, prepare a concentrated liquid feed by soaking together for a week, in equal quantities, the following: chopped seaweed (seaweed extract can be purchased from the garden centre if you cannot lay hands on kelp), shredded comfrey leaves, and mature compost and/or vermicast. Note: if you don’t have access to kelp or seaweed, the same can be purchased in concentrate form from a garden centre. Dilute your liquid feed at a rate of 1 to 4 for use as liquid manure feed.

Transplanting
Gently tap the celery plants out of their individual cells (the best way to do this can be to up end the entire punnet onto spread fingers, supporting the little plants as they all drop out of their cells at the same time). Use a trowel or dipper to create pockets, 30cm apart in your prepared tunnel house bed, pop the seedlings in (without handling their roots), and gently firm the soil around them. Water around the base of each plant to settle it into position.
If you are not prepared to pick slugs and snails off the young plants after dark with the help of a torch, scatter low-hazard slug and snail bait around the seedlings, and keep children and animals well away from the area at all times.

Maintenance
Your aim, now, is to never let your celery plants dry out, or go hungry. Temperature is weather dependent to a large extent, but you can still try your best (by opening and closing doors, windows, and vents) to keep the tunnel house within an ideal celery growing range of 12-18°C. If severe frosts arrive, cover the plants (only for as long as necessary) with frost cloth.
Celery is a very hungry plant so, where safe to do so, apply liquid feed once a week, ensuring it does not touch the edible parts of any plants.

Care for your celery, perhaps more than you would for any other edible in the tunnel house, and it will reward you with thick, crisp, delicious stems and tasty, mild leaves.

Tips
Don’t be tempted to crowd celery seedlings. The stress it causes the plants can send them to seed before they mature. Keep to the recommended 30cm apart.

If you don’t have a germination pad (and even indoor temperatures can be cool in autumn), germinate your seeds, where it is safe to do so, on top of your hot water cylinder. Contain all water in drip-proof tray under the seed raising container at all times, and cover the container with clear plastic to lock in the heat. Check daily to make sure the seed raising mix remains damp. Remove from the top of the cylinder as soon as germination has occurred.

If successfully growing celery evades you, despite your best efforts, try growing ‘celery for cutting’ (Apium graveolens). This small-leafed, low-growing celery is harvested for its mild, celery-flavoured leaves and fine hollow stems. It’s make a tasty addition to soups, sandwiches, and salads.

Parcel is a herb alternative to celery that is easy to grow, and which thrives in a tunnel house over the cooler months. Use it as you would cutting celery.

Savour the Citrus! March-Grow me now

Savour the Citrus!
We grow so many different edibles and ornamentals in our tunnelhouses, yet there’s one that is boasted about like no other – the lemon! Along with a range of other citrus suitable for undercover growing, lemons grab our attention, perhaps because they remind us of exotic winter-getaways – or even a good old
G & T! While some cool climate growers manage to coax lemons from a tree planted hard-up against a heat-retaining wall, the rest of us must rely on our tunnelhouses for this fruit, and in many ways, our undercover citrus are likely to be more perfect than those grown outdoors. Provided you know how to set up your tunnelhouse citrus for success, and how to tend to these exciting trees, you could be enjoying lemons, limes, grapefruit, mandarins, and even oranges, year-round. And the best news of all, is that right now is the time to source your plants and prepare a space for them in your tunnelhouse!

Source
Citrus are traditionally planted at the start of winter, when moisture levels are higher and can aid the rapid development of roots. The exception to the rule is if you live in a mountainous region that experiences severe winters (in which case, it pays to plant in early autumn). Choosing citrus varieties for your tunnelhouse will be largely dictated by the space you intend giving the tree (or trees). If you intend devoting your entire tunnelhouse to citrus (and some growers do, by having an extra tunnelhouse on the property just for this purpose), you won’t necessarily have to head to dwarf varieties. However, if you plan to devote just a section of your tunnelhouse to a citrus tree, or to house a container-grown citrus in the tunnelhouse only over the colder months, you may want to consider dwarf varieties.
Dwarf citrus are traditionally grafted onto the rootstock ‘Flying Dragon,’ a form of the citrus Poncirus trifoliata, which originates from Japan. And while this rootstock reduces the size of trees to around 1.5-2m in height, it doesn’t prevent the harvest of fruit from being prolific and full sized. Dwarf varieties of citrus are available at garden centres or can be ordered online.

Groundwork
Whether you plan to plant your citrus in-ground or in a container, growing medium preparation is the same. Citrus will not tolerate wet feet, and if you grow in poorly drained soil, root rot will potentially be a problem. If you are not familiar with creating your own citrus growing medium, head to the garden centre for a pre-prepared citrus mix (or use a cacti mix if you already have some). If you want to create your own growing medium, mix together in a wheelbarrow (or other large vessel) 5 buckets of lightly-mulched, untreated, organic bark, 1 bucket of perlite (or untreated organic biochar, vermiculite, or sharp sand), and 1 bucket of compost. As you are planting into the cold, dormant season, refrain from adding fertiliser (even if organic) at this stage (for exceptions, see note below).

Planting
If you are growing in-ground, dig out the existing soil to create a planting hole twice the depth and width of your nursery-purchased tree. Add a few centimetres of mix into the base of the hole. Back-fill as you plant, with your prepared mix. If you are growing in a container, choose it carefully, and be mindful of what is it made of. A terracotta container has the advantage of absorbing heat during the day, and releasing this back into the growing medium at night. However, terracotta is heavy, and it will be be more difficult to move the plant out of the greenhouse when the warmer weather arrives (placing it on a stand with wheels attached, and choosing a container with handles, can help). Plastic containers are not as attractive or sustainable as teracotta, but they are light. When it comes to the size of the container, bear in mind that the larger the vessel, the more success you will have with the plant. Having said that, any container that is twice the width and one and a half times the depth of the root ball of your tree, will be adequate.
Whether planting in a container or in-ground, if the planter bag is tightly packed with roots, and they are heading around rather than down, tease them out gently before planting, and endeavour to splay them out a little at the base as you place the plant in position. Gently firm the growing mix around the roots as you backfill, and don’t allow soil to come further up the trunk than it was previously. Water your newly planted tree to moisten (not wet) the growing medium.
Citrus will do best if planted away from drafts (they prefer a winter temperature of around 10°C), so choose a sunny spot from doors or vents.

Maintenance
While your tunnelhouse citrus is quite likely to produce fruit year-round, its active growing period is spring and summer, with sweet scented blossom appearing in spring. For that reason, the plant doesn’t require fertilising during winter. There is one exception to this rule, however: If growth patterns are a little out of character because of a warmer-than-usual cool season, your citrus may continue to develop foliage, and even begin to flower, during winter. In this case, light fertilising (about a quarter of what you would apply in the active growing period) can be carried out. Otherwise, refrain from fertilising until spring and summer, at which stage a commercial citrus-specific fertiliser can be used according to instructions. If you want to make your own citrus fertiliser, prepare a pile of of kelp mixed in with your regular compost, sterilised sheep pellets, and comfrey leaves, and leave it to rot down for 3-4 months. Apply as a 2-3cm mulch in spring, and as a liquid feed (obtained by soaking the ingredients in water) every 2-3 weeks over summer.

Your tunnelhouse will provide warmth and winter shelter for pest insects as well as your citrus, so be alert to these bugs, and spray weekly with a home-made soapy water solution (make this by dissolving 1/4 teaspoon of hard bathroom in 1 litre of boiling water, and leaving the liquid to cool completely before use). Some pest bugs also exude a residue which encourages the arrival of black sooty mould on citrus foliage. If you spot this mould, spray the leaves with milk. Growing hardy annuals (such as marigold, borage, and phacelia) in your winter greenhouse will also encourage beneficial insects into the space to gobble up pests.

The Big move
If you are container-growing citrus, they can be moved outdoors, into a sunny, sheltered location, once night time temperatures are reliably above 10°C. As you manage the relocation, watch your back, get help with the lift, and take care not to pierce the fabric of your greenhouse with any spikes on the plant. Take care, also, not to knock fruit or flowers off the citrus as you manoeuvre it through the tunnelhouse door. Once the container is in place outside, raise it up off the ground on pot feet or bricks to assist with drainage.

Top tips
Yellowing leaves
Citrus foliage easily turns yellow, and this can be for a number of reasons, from root rot to under or over fertilising. One little-known but common cause of yellowing leaves is a lack of iron. Add it to your plant’s growing medium, according to instructions on the product container, in the form of chelated iron for gardens. If using this product over winter, dilute by half.

Fruit drop
It is not uncommon for citrus to drop 80-90% of their immature fruit. Don’t be concerned about this self-thinning tendency – there will still be a good harvest left on a healthy tree.

Watering
An over-wintering citrus requires only minimal watering unless it is showing signs of active growth. Generally speaking, it is best to let the top 2-3cm of ground dry out completely before adding water (in a cold winter, this may mean the plant requires moisture only every 3-4 weeks). In warmer spells, increase watering so that leaves do not become limp or curled.

Pruning
Pruning should be carried out in early spring. Remove any dead material, and aim to open out the tree to allow air to circulate readily.

Pollination
Most citrus are self-pollinating. Enquire at your garden centre as to whether a second tree is required to assist with pollinating your chosen variety.

Frost alert!
In regions with severe winter climates, even a tunnelhouse may not adequately protect a citrus, especially if frosts come hard on top of each other. In cases of extreme cold, keep watering to a minimum, and cover the tree loosely with 1-2 layers of light, transparent, frost cloth.

Buckets of Potatoes! Grow me in February

Buckets of Potatoes!
Who doesn’t love a new potato, hot from the pot and smothered in butter and ground black pepper! But new potatoes are few and far between in February, and we need to be inventive if we want more. That’s where growing potatoes in buckets that can then be moved into the greenhouse once temperatures cool down, is the answer.
Right now, tomatoes and other summer vegetables are dominating the greenhouse, and it feels as though there’s no more space. But it won’t be long until those summer plants are spent and you’ll be ousting them to the compost. Even if they will stay in place for a few more months, tomato vines will have spaces between them as you trim off their lower leaves. And light will pour in as you pinch out leaves around trusses to let in the light to ripen the fruit. Which all means there will be space for your bucket potatoes once it’s time to move them under cover.

Source
Seed potatoes from nurseries can be hard to come by in February, so the best plan is to purchase them in January and keep them in a covered box to restrict growth until you are ready to plant them. However, if you have grown potatoes over summer, and have yet to harvest them, check for potatoes which that have been exposed to the light. You will find that some have begun to sprout short, hardy leaves. Or you may find a wild potato in the compost pile which is beginning to sprout. Remove your seed potato from the ground when you have your bucket prepared, and plant it as your seed.

Preparation
Choose a 9-10 litre household bucket or any similar plastic container or grow bag of this size and depth. Make several holes in the base of the container if it doesn’t already have these. Prepare your growing mix in a large tub or wheelbarrow. Commercial or home compost should form 80% of the mix. The remaining 20% can be made up of coconut coir, perlite or vermiculite, and sheep pellets. If not using sheep pellets, and you don’t mind using inorganic materials, add a couple of tablespoons of super phosphate to the mix, along with fertiliser pellets according to the instructions on the container. For an even better mix, add mycorrhizal fungi. This dry product is available from a number of outlets including Seacliff Organics, and it really gives plants a boost. Mix all your ingredients together thoroughly.

Planting
Fill your bucket to the half way mark with your growing mix. Place the potato in the centre of the mix, growing shoot upwards. If the seed potato doesn’t have leaves, cover it with 3cm of mix. If the seed potato already has some leaves, add just enough mix to cover the tuber, and leave no more than 5cm of the foliage exposed. Water the mix well enough to dampen, but not soak, it, and raise the bucket so that excess moisture drains away quickly. Place the bucket where it will receive plenty of sunlight (if you live in a very warm part of the country or temperatures are unseasonably high, place the bucket in dappled light – for instance, among shrubs).

Maintenance
Each time the foliage of your seed potato reaches a height of 15cm, add growing mix to the bucket so that only 5cm of leaf is protruding. Keep the growing mix damp but not wet, and water it with a liquid feed every week. The liquid feed can be made by soaking in water 2 cups of sheep pellets and some chopped seaweed and comfrey leaves. If the weather is very warm, you may like to add a mulch of straw or pine needles over the growing mix (but not the potato foliage) to help keep the soil damp. In strong winds, give the potato plant shelter.

The big move
Once cooler autumn temperatures arrive, carefully move the potato in the bucket into the greenhouse. Place it in a position where it will receive plenty of light. Remember that your greenhouse is providing optimal growing conditions, not just for your potato, but also for sap sucking insects such as aphids. If you spot these pest, gently rub the potato foliage between your fingers to squash them, or spray with a soap and water mix made from 1/4 teaspoon of hard bathroom soap dissolved in 500mls of boiling water (cool thoroughly before placing in a spray bottle). In the heat of the greenhouse, your potato may need watering more frequently.

Harvest
Bucket-grown potatoes take around 60 to 70 days to produce a crop. However, as you are growing your potatoes into autumn, you made need to allow a little longer. Check to see if the potatoes are read by gently removing a little growing mix from the bucket or by feeling down in the mix with your fingers.

Tips
The ideal temperature for potatoes to grow in is around 10-15°C. Use a thermometer to check the temperature in your greenhouse, and delay placing your potato plant under cover until the temperature suits it.

It is not necessary for the potato foliage to die off before harvesting your new potatoes.

If you live in a mountainous part of the country, frosts can arrive early, and a hard frost can damage potato foliage, even when the plant is in the greenhouse. In very cold regions, cover you potato with frost cloth if you are expecting temperatures to drop below zero.

If potato psyllid is a problem in your region, protect your potato from this pest by covering the foliage with a 0.3mm mesh.

In very warm weather, keep the roots of your potato cool, and its leaves in the sun, by placing other containers around it.

If it is possible to choose a variety of seed potato to plant, go for an ‘early.’

A passion for Fruit! Grow me in January

Grow Me Now!
January

A Passion for Fruit!
You may have seen them, recently, hanging like gorgeous Christmas decorations from their vines. Passionfruit, which take 2 to 3 months to mature, are in the process of ripening in January, with the skins of pickable fruit turning a deep purple (or gold, depending on variety) from February through to June. While the vines are tropical, they can also be grown in frost prone regions when planted in an unheated tunnelhouse. Bear in mind, however, that although passionfruit vines will tolerate frosts of minus 1-2°C, more severe frosts (or even lighter frosts which continue for more than short periods), will kill off new growth. This poses problems for those growing in mountainous regions such as Central North Island and inland Otago. But, outside of areas that are prone to severe cold, not only will a tunnelhouse provide the warmth the vines crave, it will also offer the shelter needed for the plant to thrive.

Source
While mid-summer may seem an unlikely time to introduce a new perennial to your tunnelhouse, passionfruit can be planted at any stage from mid-spring to mid-summer (or even later if temperatures remain warm). The vines are readily available in nurseries and garden centres, but take care which variety you choose*, as some grow more vigorously than others and are less suited to undercover growing (yellow-fruiting passionfruit vines are particularly fast growing). Additionally, although passionfruit vines are self-fertile (both male and female flowers appear on the same plant), they will fruit better if planted in pairs. Additionally, some varieties are self-incompatible, and must have a partner plant in order to set fruit. Ask your nursery for advice.
Passionfruit vines survive for around 4-5 years, only, and have a long taproot, so be weary of accepting offers of a plant that needs to be uplifted from its in-ground growing position. Varieties grafted onto rootstock should never be uplifted as the disturbance can result in the development of unproductive suckers.
*Never plant banana passionfruit (Passiflora tripartita). It is illegal to grow this invasive species.

Ground work
Before you prepare the ground to receive your passionfruit vine, you will need to erect supports for this vigorous climber. The weight of the vine, combined with the weight of the fruit, means the supports need to be robust (poles dug into the ground, with number 8 wires or frames of builder’s reinforcing iron, between them, are ideal). Use the maximum height available to you but avoid extending the support across the roof of the tunnelhouse or you will lose valuable heat and light.
Passionfruit vines are hungry plants which require excellent drainage to thrive. Prepare the growing hole (which should be twice the width and depth of the container the plant is growing in) by digging out spent soil, and replacing it with rich compost, blood and bone, and seaweed. (If the ground below the hole is clayish, dig deeper, and add a 10 to 15cm layer of fine stones or river gravel before topping up with your growing mix. If you don’t have the wherewithal to provide organic ingredients, choose a suitable growing medium, such as that used for citrus fruits. A pH level of 4.5 (strongly acidic) soil will help with fruit production.

Transplanting
If you have space in your tunnelhouse for two plants, space them approximately 2 metres apart. Before transplanting, water the growing site well, and leave it for an hour, to drain. Plant in the cooler part of the day (early morning or evening) by first gently teasing out the roots from the root ball of the vine, taking care not to break them. Place the plant in the prepared hole, ensuring that the soil does not reach above the level it was when the vine was in its pot. Water again. Ensure the tunnelhouse is well ventilated.
Pollination will be aided by the movement of insects. To draw them into your tunnelhouse, grow flowering plants in the tunnelhouse as well as close to its doorway (growing flowering plants in pots means you can replace them, when their blooms are spent, with others that are coming onstream.

Maintenance
Passionfruit vines are vigorous growers, so they routinely use up nutrients from the soil. Replenish these by topping up the area around the vine with more mature compost and weekly feeds of organic liquid manure or a recommended fertilizer. Cut back on blood and bone as the vines gain height and begin flowering, as high nitrogen levels create foliage at the expense of fruit. At pre-flowering and flowering time, increase levels of potassium (seaweed water, for organic growers).
Keep a watch for sap-sucking insects such as aphids, and squash them with your fingers in the first instance. If the pests persist, apply a spray made from 1/4 tsp hard bathroom soap dissolved in half a litre of boiling water that has been left to cool completely. Repeat every 3-4 days. Note: if you are growing organically, there is no need to completely rid the plants of pests – a healthy balance is what you are aiming for because the general strength of the plants means they can hold their own against a degree of pest attack. Be sure to gather up fallen leaves to avoid providing hiding places for pest insects.
Keep the tunnelhouse well ventilated, day and night, and harvest fruit as soon as it is ripe to take the pressure off the plants.
When keeping vine growth under control, remember that fruiting will occur on new growth, so don’t snip this all off! Prune in spring, only after frosts have abated, so that you do not stimulate new tender growth that will be knocked back by sub-zero temperatures. Prune in autumn to retain the shape of your vine, and to allow air to circulate.

Tips
Always use snips to harvest, rather than pulling off the fruit, which can damage the vine.

In very frosty conditions, cover the vines with a layer (or two) of frost cloth for extra protection.

Spraying the vines with a seaweed tonic solution can help increase resistance to frost.

Stop feeding, and reduce watering over the coldest months to discourage new growth which could be cut back by frost.

The vines don’t like competition, so keep the ground beneath them weeded and mulched.

Once night time temperatures drop to below 19°C, flowers tend to drop off, and those that remain require insects to pollinate them.

Sweet Table Grapes- Grow me now in December

December Grow Me Now!

Sweet Table Grapes
If you’ve ever been disappointed (and who hasn’t) by those tasteless, generic Australian and South American table grapes that appear in our supermarkets, it’s not surprising. Supermarket grapes are often picked well before their sugar content is at its best, in order to ensure they travel well. The result is that they have tough, sometimes bitter, skins, and their juice tastes like flavourless sugar water. But the thing is, we know we can grow much better grapes in our own greenhouses. All it takes is the determination to carry out a few simple tasks, especially in the month of December.

Source
Table grape vines traditionally go into the ground in late autumn or early spring. ‘Albany Surprise’ (large, juicy, blue-black fruit with a spicy flavour) has been a favourite indoor table grape for many years, and well cared for, vines can produce bunches weighing between 200 and 350g. ‘Iona’ is another hardy grape that suits cooler regions, while ‘Canadise’ is a sweet, red, seedless grape delivering up the goods in mid season. Always source your vines from close-to-home nurseries that will understand the varieties that suit your area best.

Ground work
Although it sounds extravagant to devote an entire greenhouse to a grape, doing so will give the best results. That’s because, a grape, in full leaf, shuts out a good deal of light, and nothing much else will thrive beneath its canopy (of course, over the winter months, when the vine is deciduous, that’s when you can use the ground beneath to grow a winter vegetable crop, or to store potted citrus and other frost tender treasures).
Before purchasing a grape, it pays to secure wire supports across the width of the greenhouse, above head height. This will allow for eventually training the vine back and forwards across the supports so that the bunches of grapes hang down into the ripening heat and light, rather than getting caught up among the shade of leaves and leaders. Training the vine across supports also helps to keep foliage away from the glass or skin of your greenhouse where it can attract condensation, remain damp, and encourage mildew to set in.
Ventilation will be required to maintain the health of the indoor vine, but it also pays to bear in mind that birds are one of the greatest threats to the crop, followed by wasps. So, if your greenhouse doesn’t come with a mesh door, get one, or create your own with a mesh curtain as soon as young fruit appears on the vines. You will also have to cover vents with mesh to keep wasps at bay (do so carefully when working around glass) .

Sowing and planting
If you don’t wish to be forever watering your grapevine, plant it close against the side of your greenhouse, and lead it into the interior of the structure by safely removing a section of glass or polythene skin (where this is not possible, consider leading the vine in under the foundation of your greenhouse).
The hole you dig for the vine should be twice the size of the root ball. Dig into the hole a mixture of compost, blood and bone meal, manure and, if the soil is heavy and clayish, a shovel or two of fine grit to assist with drainage. PH should be between 5.5-7.0, so adjust with lime if necessary. Keep the ground around the planting moist for the first year by watering once a week in dry conditions.

Maintenance
Before growth properly takes off in mid-spring, the root area can be sprinkled with an organic fertilizer and an extra feed of dried blood. When the leaves are fully open, a high potassium fertilizer will benefit the vine. To supply it, soak kelp in fresh water for a few days, then water onto the root area. Continue with this regime every week throughout the growing period, stopping only when the grapes begin to colour up. As the heat increases, mulch around the root area of the vine to keep the ground cool.

Pruning
As the vine puts on spring growth, it will produce laterals (this is the new growth which sprouts from the woody ‘trunk’ of the vine). In a new vine, several of these laterals are left to grow unchecked. Eventually, they will form the main, woody framework of the vine. Other laterals, however, should be pinched out at the ends after they have developed 2-3 bunches of grapes. ‘Pinching out’ doesn’t stop the rampant growth altogether, however. You will need to repeat the treatment throughout the summer. This will also help to thin out leaves, and let in the light.

Pollination
Grapes are self-pollinating, but they do appreciate a helping hand from their grower. Each time you are in the greenhouse, gently shake the stems to encourage pollen to fall.

Pest and plague
Although many growers use a range of chemicals to stave off mildew, one of the best organic treatments for undercover grapes is seaweed water. Sprayed onto leaves early in the day (so the foliage is dry again by night) it appears to deter fungal disease such as black spot and mildew.

Post harvest
Winter pruning of greenhouse grapes is essential for the good of the following year’s crop. Old wood from which bunches have grown, is removed, while new laterals that will support next year’s harvest, are tied down.
When work on the wood has been completed, it’s time to check supports, mend any holes in the skin or glass, or in the mesh bird covering – because it won’t be long until the next season is on its way.

Tips
If you prefer to grow your undercover grape in a pot, rather than outdoors, choose a large-ish container at least 30cm in diameter, and 65cm deep.

Use scissors to harvest so you don’t damage the plant tissue with a tug.

If you are looking for the perfect shaped bunch, don’t be afraid to trim off a few grapes from a bunch (while they are still very small) with nail scissors.

Remove tendrils that are not supplying obvious support (they only get tangled in the bunches).

Herb Heaven- Grow me now in November

Herb Heaven

When it comes to preparing tasty food, it’s the little things that count – and many of them are herbs! The flavoursome morsels that bring salads, dressings, pestos, pizzas, curries, and barbecue foods to life are always better, fresh. So, although we can reach into the pantry for them, in a dried or processed form, they are much more delicious when we grow them ourselves. And the good news is, that although many of the tastiest natural flavour boosters require warmer growing conditions than our climate can provide, we can make a home for them in our tunnelhouses! This month, we take a close-up look at three flavour-packed, heat-loving herbs you can grow at home, undercover. They are curry tree(Murraya koenigii), basil, and lemongrass (Cymbopogon).

Source

The curry tree (Murraya koenigii)should not be confused with the curry bush (Helichrysum italicum), a common garden plant with grey-green aromatic leaves. The curry tree supplies the fragrant leaves that are used so frequently in East Asian cooking, and it can be sourced from a number of places, including Trade Me, where it can be found for around half the price it is sold for in garden centres. The plant can also be grown from seed, and experienced gardeners may like to try growing it from cuttings.

Basil is a staple for salads and authentic Italian dishes. Seeds and plants are readily available in the warmer months from garden centres, plant stalls, and friends. When choosing plants, take great care to avoid those that have pest insects on them. The leaves of basil are tender, and sap suckers feed on them voraciously, and breed up in no time at all. Basils come in so many different forms, so when selecting plants or seed, check the description carefully and purchase according to how you intend to use the leaves.

Lemongrass is a favourite condiment in Southeast Asian dishes – and a must for Thai and Vietnamese foodies. It can be sourced very cheaply Trade Me, or from garden centres and gardening friends. It is a magnet for aphids, so be discerning before you purchase, or accept, rooted pieces.

 

Ground work

Depending on variety, a curry tree will grow to over 2m high. When growing it in your tunnelhouse, a container is perhaps the more useful option for keeping the plant it to a reduced size. This will also prevent roots invading the tunnelhouse beds. Wherever you grow your curry tree, the ground should be free-draining and nitrogen-rich (incorporate compost and bone meal to help with this, or choose a nitrogen-high fertilizer). If your tunnelhouse has sunnier spots than others, give the curry tree the sunniest place you can spare.

Basil is a plant which enjoys drier conditions than most other greenhouse edibles. Grow it in a pot, or in a situation where it can dodge regular waterings. In terms of soil requirements, it will be happy with a rich, organic mix as long as it is very free-draining. Basil enjoys the sun, but is also comfortable growing beneath the likes of tomato vines that have had their lower stems pruned to allow in the light.

Lemongrass enjoys a rich, free-draining growing mix, and loads of sun. This is your cue to add blood and bone and a handful or two of sharp sand (fine river-grit) to the growing site, and to position the plant in the brightest spot in the tunnelhouse,

 

Sowing and planting

When potting up a curry tree, choose a container that is at least 30cm deep, and which is 6cm wider than the root ball of the tree. Ensure soil does not reach above the base of the trunk. Seeds should be covered in soil to twice their depth, and the soil topped with clear plastic to lock in warmth and humidity.

Basil seedlings transplant easily, but it pays to keep soil around the roots when doing so. Seed will also germinate readily providing it is pressed into the soil and not covered – it requires light to germinate. To keep the seed damp, cover with a piece of clear plastic until signs of sprouting occur. Basil plants can also be grown from cuttings placed in water. When rooting cuttings in this way, strip off a third of the upper leaves from the cutting, and place at least the lower third of the stem in water. Change the water, daily, and pot up or plant the stem in the ground once roots have been growing from it for 10 days to 2 weeks.

Lemongrass is usually grown from a rooted piece or clump. Pop it into the ground, and firm the soil around the base of the stems. Alternatively, grow it in a container which is 6cm wider than the piece or clump you are planting. Lemongrass can also be grown from seed. Sow the seed in clusters of 3-4, and cover to a depth of 5cm. Keep the soil damp but not moist.

 

Maintenance

Cury trees and lemongrass appreciate a high nitrogen liquid feed every 3-4 weeks during the active growing period. Basil can be fed in the same way every 2 weeks (but only on a day when the liquid will evaporate as quickly as possible).

Curry trees require careful pruning to keep them to a manageable height, and to ensure they produce as much leaf as possible. For details on pruning, head over to HowandWhentoPrune.com for some great advice.

Basil plants produce best when their growing tips are nipped out once the stems reach a height of around 15cm.  It will not survive over a cold winter, even undercover. Towards the end of the season, take a few stem cuttings and pop them into water to root. These can then be potted up and placed on a sunny window ledge to produce a few flavoursome leaves over winter.

Lemongrass can be left to grow over the warmer months, but as winter approaches, cut the foliage back to 15cm in height. In cooler parts of the country, you may want to cover the plant in frost cloth. In mountainous regions, dig up and divide the plant. Pot up small clumps to keep inside on a sunny window ledge, and replant in the tunnelhouse again in spring, once frosts have abated.

 

Tips

By removing the flowers from your curry tree, you will enable the plant to put more energy into leaf growth.

 

If your curry tree has maxed out in height, and can no longer fit comfortably in your tunnelhouse, reduce its height by two thirds. This will encourage the plant to put out new growth around its base.

 

When harvesting lemongrass, choose the thickest stems – they are usually to be found at the outside edge of clumps.

 

Lemongrass benefits by being lifted and divided ever 3-4 years.

 

Basil is quick to succumb to aphid and whitefly invasion. Grow it among insect repelling plants such as calendula and nasturtium. Plant it in several different places in the tunnelhouse, and removed infested plants before the pests move to another site.

 

Basil doesn’t like wet (or even very damp) feet. It can benefit from being grown in a container if you don’t have the time to skirt around it when watering other greenhouse plants.

 

 

Creative with Cucumbers-Grow me now in October!

Creative with Cucumbers!

Crispy, crunchy, and thirst quenching – cucumbers are a summer supermarket staple. So much so, that some Kiwi kids are said to believe these curcubits grow inside a plastic skin! If you’re not into the shrink-wrap, shopping trolley version of cucumbers (and their gherkin cousin), now is the time to start growing these delicious vegetables in your own tunnelhouse. 

Cucumbers require reasonably high temperatures (between 23and 29 degrees Celcius) to thrive. If you live in a warmer part of the country, October is the month to pop the seeds into the tunnelhouse itself. If you’re in a cooler spot, wait until later in the month for this, or delay until November, or even (in the case of mountainous regions) December. Regardless of where you live, if you are still enjoying your autumn and winter planted veges from the tunnelhouse, and plan to do so right through spring, there’s no need to oust them prematurely to make way for cucumber plants. This obliging vegetable will happily wait to be planted until you have space ready for it.

 

 

Source

We live in an age where every gardener wants to be a seed saver. That’s a good thing, but sometimes, saving your own cucumber seed doesn’t work out quite as you expect. That’s because many of our favourite varieties are ‘hybrid’ cucs. A hybrid vegetable is the result of two different varieties of plant being deliberately cross-pollinated to create a desired result. Unfortunately, when the seed of the progeny is sown the following year, it is unlikely to produce a vegetable which is identical to its parent. It will have reverted to an earlier variety, and in the case of your cucumber, it will not be the one you were hoping for. If your favourite cucumber variety is labelled ‘F1,’ that’s your clue that it won’t deliver the goods second time round, and that you need to start from scratch with store-bought seeed.

Cucumbers come in a wide range of varieties, so there are plenty of choices. If you are growing in a limited space, choose a compact, bushy variety or one such as the Lebanese cucumber, which produces smaller fruit. If you’re a small household, and want to avoid waste, choose a mini variety such as Cucumber Crunchy F1. And if you’re a pickle-lover, be sure to head to the mini-cuc cousin, the gherkin.

 

While cucs and gherkins grow readily from seed, they are also widely available in garden centres. If buying potted seedlings, take a magnifying glass with you, and check carefully, on both sides of leaves, for pest insects and their eggs. If there are any signs of invasion, leave the plants on the shelf!

 

Ground work

Cucumbers (and gherkins) enjoy growing in ground which is fertile, textured, and humus-rich. When preparing a growing spot for them in the tunnelhouse, dig in plenty of safely made, mature, nitrogen-rich compost. Although cucumbers like a little lime, your tomatoes don’t, so if you plan to use the same ground next year for tomatoes, skip the addition of lime (something the cucumber plants will tolerate). Water the ground well, 24 hours prior to sowing seed or planting seedlings.

Cucumbers resent having their roots disturbed, so if you plan to train these climbing plants up stakes or trellis, anchor your supports firmly into the ground before you place the seeds or plants in the soil. If you don’t, you will cut through delicate roots, and your plants my sulk as a result. If you will be using twine to support your growing vines, put these in place before you plant so that you avoid  standing on the ground and compressing the soil.

 

Sowing

Sowing into pots

If you are raising your seeds in containers prior to planting out the resulting seedlings, sow into peat pots (or pots which you make yourself from toxin-free paper). This means that you will be able to plant the seedlings, pots and all, into the tunnel house when the time is right, without disturbing roots. Note: some gardeners have tried using cardboard tubes (such as the sort which come inside kitchen wrap) as planter pots. However, these can be sturdier than they look, and can inhibit root growth before they are ready to decay in the soil.

Fill your seedling pots with quality seed raising or vege mix, water it well, and sow the seed, about 1cm deep, into the growing medium. Cover the seed with loose soil (don’t compress it). If you have a seed raising mat, pop the pots onto it. Covering the pots with a sheet of plastic (at night, only) can speed up germination. If the weather is slow to warm up, water liquid feed onto your seedlings to provide nutrient until they can be transplanted into the tunnelhouse.

 

Sowing directly into the tunnelhouse

Sow your seeds into prepared ground (see above) in groups of 3. Each group of seed should be sown 60 to 70cm apart. Once the seed germinates and grows on for a week, pluck out the two weakest seedlings from each group, and let the third grow on.

 

Maintenance

Once the seedlings are established in the tunnelhouse, liquid feed them with nitrogen-rich fertilizer every 3 weeks after flowers appear on the vines. This feed can be brewed by soaking safely made compost with blood and bone, seaweed, and comfrey leaves. Keep the ground beneath the cucumber plants weeded, and the tunnelhouse well-ventilated to encourage the air flow necessary to deter fungal disease. Tie the vines to their supports regularly so that the foliage does not collapse back onto itself.

If you spot signs of ‘rust’ on leaves, snip off the affected foliage and dispose of it in your waste bin (not the compost). If you see signs of aphids, gently squish the insects with your fingers, and treat the foliage (not fruit) with soapy water spray*every 3 days until the infestation reduces or disappears.

*Make your own soapy water spray by dissolving half a teaspoon of hard bathroom soap in 1 litre of very hot water, cooling the water completely before adding it to a clean spray bottle.

 

Tips

Most cucumbers require insect pollination to form fruit. Encourage insects into your tunnelhouse by planting insect-friendly flowers around the doors, and by moving one or two potted marigold plants into the greenhouse when they are in bloom.

 

Harvest your cucumbers as soon as they are mature so that the vines do not have to work unnecessarily hard to support them.

 

When using ties to anchor the cucumber vines to their supports, avoid soft woven, cotton twine. It tends to hold onto moisture and can cause fungal disease to develop in the stems of the plants. Choose strips of nylon pantyhose, instead

 

Drooping, wilting foliage may not be due to a lack of moisture in the ground. Over-watering can do even more damage as it swamps the soil and prevents oxygen reaching roots. Water only when the ground feels dry up to the second knuckle of your finger. Water deeply, to encourage roots to grow down into cooler ground.

 

Water your cucumber plants in the early morning so that excess moisture evaporates during the heat of the day and does not collect at night to cause a damp, humid environment.

 

Discourage disease by always water the plants from the base, avoiding wetting the foliage.

Sold on Strawberries! Grow me now in September

Grow Me Now

 

September

Sold on Strawberries!

Strawberries are a longed-for summer treat, but they so often disappoint. From failing to fully pollinate, lacking flavour, becoming marked by birds, slugs, and snails, rotting before they’re ripe, and simply not returning a decent number of berries, strawberry hassles mean many gardeners give up growing this delicious fruit. If this sounds like you, there is another way to get the crop you crave – and it’s by growing your strawberries in a tunnelhouse. What’s more, strawberries in the tunnelhouse ripen so much earlier than those outside, that you’ll have the ground free for tomatoes and other heat-lovers by the time you need it. As a bonus, tunnelhouse strawberry plants are likely to produce more fruit than those grown outdoors, so you don’t need the same number of plants. And your berries will be super-sweet because of ripening in the warmest of conditions.

 

Source

Strawberries fruit from spring through until autumn, depending on variety, with ‘Monetrey’ being one of the latest varieties. If you have space in your tunnelhouse to grow strawberries throughout the warmer months, choose a range of varieties. If you need the space for heat-lovers in late spring, choose an early maturing strawberry such as ‘Pajaro.’ If you are already growing strawberries in your outdoor garden, and the variety suits your purposes, dig up a few young plants that have formed on ‘runners’ last season, and use them in your tunnelhouse.

When purchasing plants from the garden centre, inspect them carefully (on the underside of leaves as well) for signs of aphids and other sap-suckers. Once these pests reach the warmth of your tunnelhouse, they will romp away if not checked.

 

Groundwork

Whether you intend growing your undercover strawberries in the tunnelhouse bed, or in containers, preparation is the same. The soil needs to be rich, loose, and free draining. Dig in lashings of compost made with ingredients that include sterile animal manure and decayed kelp, and add a sprinkling of bone dust. Strawberries are acid-loving, so skip the lime. If you are using inorganic fertilizer, choose one specifically for strawberries, or which has a balanced NPK ratio. Dig all ingredients in deeply, and water the beds or containers well. Leave planting until the next day, once the growing medium has soaked up the moisture and had time to drain.

 

Transplanting

Strawberry plants can be grown a little closer together in the tunnelhouse than you would outdoors because there is less leaching of nutrients, undercover. Drainage is also more controlled so there is no need to raise the plants up on mounds. Simply make shallow depressions in the bed (or your containers) about 1.5 hand widths apart. Press the plants firmly into the soil, and bring the soil around them without covering their central crown (the point in the centre of the plant from which the leaves grow). The crown should always be above soil level. Lay a light mulch of straw or untreated wood shavings around the plants.

 

Maintenance

Water the plants before the soil dries out completely, and give them a liquid feed every 7-10 days until fruit begins to set. Check carefully at night, with a torch, for slugs or snails, and remove any you find. Once fruit begins to ripen, keep it free of fungal disease by ventilating the tunnelhouse day and night. Cover doors and vents with netting to exclude birds, or use a specially fitted Tunnelhouse screen door. Snip off (never pull) runners as they appear (‘runners’ are new, young plants which form on a long stem which branches off from the main plant). This will help keep your plants fruiting. Harvest the berries with scissors.

At the end of the fruiting period (when the plants are no longer producing flowers), remove containers of plants outside and into a sunny position. If you have grown your strawberry plants directly into the greenhouse bed, dig them up, and replant them in a spare space in the outdoor garden.

 

Tip

If using pea straw mulch, take great care to get it from an organic source or to make certain it has not been tainted with Glyphosate. Even a trace of the chemical will damage or kill tomato plants.

 

If signs of fungal disease appear, move mulch away from the plants to allow for greater air flow. Remove any diseased fruit immediately.

 

Towards the end of fruiting, allow a handful of runners to develop. Press them into containers of potting mix while they are still attached to the parent plant. Once they are rooted, snip off the runner. These young plants will provide you with next year’s greenhouse crop.

Tempted by Tomatoes? Grow me now in August

Grow Me Now!

August

 

Tempted by Tomatoes!

They’re the summer favourite that gets gardeners talking – and the one plant, more than any other, that sees a grower invest in a tunnelhouse. Which makes it even more unbelievable that this South American native once aroused so much suspicion when first introduced to Europeans, that they had to be persuaded to eat it! Today, the popularity of the tomato continues to grow, and the trend, over the last few years, toward planting heritage tomatoes, has only increased excitement about the fruit. While Kiwis in cooler regions grow their tomatoes under cover, those in warmer climes are often turning to crop tunnels to provide a well-protected, blemish-free crop. 

 

Source

The depths of winter may not feel like the time of year to be germinating tomato seed, but unless you want to be buying seedlings at the garden centre (where there is limited choice of variety) August is certainly the month to start sowing. When choosing seed, there are a few decisions to be made. Tomatoes fall into two broad categories: indeterminate (vine-style) and determinate (bush-style) plants (both are suitable for a tunnelhouse or crop tunnel). Within these two categories, both commercial and heritage tomato varieties are available. The garden centre will be able to supply you with seed of regular tomatoes, and a few heritage varieties, but for more exotic choices, check out Kings Seeds, Koanga Institute, and Trade Me. Or ask around on Facebook gardening groups.

 

Ground work

Sow your seed into a punnet of quality seed raising mix placed on a sunny window ledge or propagation pad. Tomatoes prick out easily, so once the seeds have germinated, and have their first true leaves (rather than their ‘germination leaves’), transplant them into individual containers of tomato potting mix. Be guided in container size by your climate, and the indoor or propagation space you have available. (In cooler parts of the country, it will still be too cold to place the seedlings in the tunnelhouse in September, or even October, and they may need to grow on, indoors, for several weeks. Make sure their pots give them the root space they will require.)

Once your tomato seedlings are growing, it’s time to prepare your tunnelhouse to receive them. Tomatoes can be in the ground for 6 months or more so it’s important to pile in the nutrients from the start. Dig in plenty of quality compost (a source of nitrogen, but also of the potassium and phosphorus, on which tomatoes thrive). If your compost hasn’t included kelp, add it to the soil, now.  Tomatoes prefer a pH of 5.5-6.5, so don’t add lime to the ground unless it is particularly acidic (a soil test kit can help establish this). The roots of tomato plants are shallow, but long, and stretch out horizontally. They don’t enjoy negotiating obstructions, so mix all your ingredients into the bed of the tunnelhouse well, and crumble up any lumpy material. Water the bed deeply, at least twice before planting, and keep it weed-free.

 

Transplanting

Tomatoes can go into the greenhouse anytime from late August onwards, depending on where in the country you live. If your location is prone to frost then plant in the tunnelhouse late October or even November, especially if the weather is cooler. When transplanting, use a trowel to create pockets 70cm to 90cm apart. If using stakes (rather than twine) as supports, push them into the soil beside the holes before you plant, so you don’t disturb roots. Water each planting hole well, upend the seedling container to ease out the tomato plant, and place the seedling gently in the hole. Lightly firm the soil around the base of the plant (note: you are unlikely to kill a tomato seedling by planting it too deeply, so if your plant is ‘leggy,’ set it down further in the hole, for added support).

Maintenance

As your tomato plants grow, water them deeply once or twice a week. (This encourages the roots to grow down to cooler soil. More frequent, shallow watering, only encourages roots to invade the surface area, which quickly leads them to over-heat and dry out in hot weather.) Water the plants with a liquid feed of kelp and sterile animal manure every 7-10 days until flowering commences. After that, water with liquid kelp only (too much nitrogen encourages foliage at the expense of flowers).

Unless you are growing grafted tomatoes (in which case refer to the growing instructions that came with them), remove the lateral shoots from indeterminate (vine) tomatoes to encourage the plants to grow up, rather than out, and to hasten flower production. Tie the vines to stakes, or guide them around twine supports, as required. Determinate (bush) tomatoes will also require support. Provide it in the form of a framework or tomato cage.

Keep a watch for sap-sucking insects such as aphids, and squash them with your fingers in the first instance. If the pests persist, apply a spray made from 1/4 tsp hard bathroom soap dissolved in half a litre of boiling water that has been left to cool completely. Repeat every 3-4 days. Note: if you are growing organically, there is no need to completely rid the plants of pests – a healthy balance is what you are aiming for because the general strength of the plants means they can hold their own against a degree of pest attack.

Keep the tunnelhouse well ventilated day and night, promptly snip off any leaves that attract disease, this will also help with airflow and light transmission and harvest fruit as soon as it is ripe to take the pressure off the plants.

 

Tips

Some gardeners like to grow their tomatoes in fresh soil each season, but if disease hasn’t been a problem in the previous season, you may decide this isn’t necessary. 

 

Always try to grow your own tomatoes from seed. To buy at the garden centre is to risk bringing aphids, white fly and other pests into your tunnelhouse.

 

When sowing seed, cover the seed containers with a sheet of perspex or glass to prevent mice digging them up (in August, rodents are on the hunt for any food they can find).

 

If raising seed without the aid of a germination pad, try popping the seed containers inside a plastic bag as they sit on a sunny window ledge. Leave one end of the bag open to avoid over-heating and ‘cooking’ the seed. This mini greenhouse effect can hurry along germination.

 As soon as you start sowing tomato seed, begin soaking kelp and sterile animal manure in a large barrel of water. This will be the liquid feed for your plants until flowering time commences.

Tomatoes that are indeterminate love to grow in height. Use your top aluminium purlin in the Tunnelhouse as a support to tie you strings on and these can be adjusted as the plant grows. A simple tent peg or similar at the base of the plant can be used to tie the string on and wind around the stem of the plant as it grows. 

Once you discover a variety of tomato that you favour, keep the seed from it for sowing again next season. To collect seed, take pulp (containing seed) from a ripe tomato, and smear it onto a folded paper kitchen towel. Leave it to dry thoroughly over a period of days, then snip up the individual seeds (paper towel and all) and store in a sealed envelop or jar (don’t forget to label with the date and description).