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Lighten up- Grow lights for Winter

Lighten Up!
How to use grow lights to boost plant health over winter.
Mid-winter is a time for celebration, and many of us use lights as part of the fun. But lights also have a more serious use for tunnel-house growers, especially in the shorter days of our coolest seasons. That’s because plants require light, as well as warmth, if they are to thrive. And no matter how warm it gets inside a tunnel-house in the ‘off-season,’ unless you master the skill of stopping the Earth turning, you cannot increase the natural daylight hours available to your plants! What you can do, however, is use grow lights. But before we get onto that, let’s take a closer look at just how demanding plants can be when it comes to light.

Plants can be demanding!
All plants require sunlight in order to photosynthesise and remain healthy. More importantly, they require an adequate number of light hours in order to achieve their full potential. Each plant has its own preference when it comes to the number of light hours it requires, and also the strength of that light. The peace lily, for example, prefers 12-14 hours of filtered (low level) light, but can flower when given just 2-4 hours of light. On the other hand, a tunnel-house tomato plant requires 8 hours of bright light through all its growth stages. Even the humble cabbage demands a healthy dose of light – around 6 hours to keep it happy, and 8-10 if it’s to thrive. You can read more about how many hours of light various vegetables require at Ponics Life.


Answering the call for help

If a tunnel-house grower is to provide their plants with the light they require year-round, then over the short-day seasons of late autumn to early spring, they will need to provide them with some artificial light (known in the gardening world as ‘grow-lights’). Lights which aid plant growth are usually referred to by ‘spectrum’ range. That’s because light waves come in different colours, and each colour can help a plant in different ways. For example, red light helps with fruiting and flowering. Blue light is important for the growth of leaves, stems, and roots. Green light is good at penetrating through leafy canopy, and white light is especially good for seedling development.

Height matters, too!
If grow-lights are to be most effective, they need to be placed at the correct height above your plants. The strength of a light is measured in watts, and the kind of LED (light-emitting diode) grow-lights that are used in a home tunnel-house are usually around 5-20 watts. This means they should be placed approximately 30cm above your vegg plants. As the strength of grow-lights differ, it can help to think about it like this: generally speaking, the younger your plants, the further away the light needs to be from them. And the stronger the lights are, the higher up they need to be.

Take me to them!
Grow-lights aren’t difficult to find. But when you do locate them, whether in a garden centre or on a site such as Trade Me, it’s easy to get bamboozled. Some lights are ‘full spectrum’ i.e. they have the full range of wavelengths to help each aspect of plant growth. Other lights are pink & blue (often called ‘purple lights’ because that’s the glow they give off when switched on.) Purple lights are helpful, too. Grow lights often come in rigid strips or panels, or they may be mounted on a soft strip on a reel. Both options offer different lengths or dimensions.

Safety first
Most tunnel-house growers won’t have an approved electric socket in their greenhouse, and to get one professionally wired in (which is what is legally required – a field cable isn’t a safe option), can be costly. But there are alternatives (which you should always discuss with your electrician before proceeding with). Alternatives include purchasing grow-lights with a USB attachment which can be plugged into a portable power bank similar to the one you may have as a backup for charging your mobile phone.

Timing is everything
However you decide to install grow-lights into your tunnel-house, be aware that they will need to switch on and off in order to provide the required number of hours of light your plants crave, and no more or no less. If you you don’t want to be traipsing back and forwards to the tunnel-house every few hours, you may want to invest in an automatic timing device that is compatible with your grow-light system.

Tips for working with grow-lights
Different plants require different amounts of light. When growing in the tunnel-house, group the same variety of plants together to help with logistics.

Even though it’s daylight in winter, much of the sun’s light may still be hidden behind cloud cover. On grey days, some growers leave their grow-lights on for a few hours to supplement the available natural light.

Choosing soft-tape grow lights which come on a reel means that you can roll them up over summer for easy storage.

Grow lights come in a wide range of prices. Purple style grow-lights on soft tape can often be purchased via Trade Me for just a few dollars.

June- Fresh Greens

Fresh Greens – for you and your feather friends!
Unless you live in one of the more balmy parts of the country, June is not the best month for sowing or transplanting in the tunnel house. Except if you choose to grow microgreens specially suited to the time of year. Cool season microgreens are a tasty selection of fast-growing leafy greens specially suited to the cooler months. And because they are designed to be harvested when just a few centimetres high, and to regrow, you will be able to access some fresh salad ingredients in just a few winter weeks. But fast-growing greens aren’t only for humans! In winter, your chickens are craving fresh treats, too, and it’s the very time of year when their pickings are slim. That’s why we recommend growing a specially designed mix of ‘chicken microgreens’ for your feathered friends. It will keep them healthy, and in the best possible condition for egg-laying.

Ground work
Microgreens are fast growing, but in winter, they have to work extra hard to germinate and put on leaf. That’s why ground preparation is so important. Some microgreen seed (such as beetroot) is large and robust. Other microgreen seed is tiny (think mizuna and mibuna).
When preparing tunnelhouse ground for your own microgreens, focus on how you can help the tiniest seeds to germinate, and work extra hard to get the soil as fine as possible. To do this, use a garden fork (or hand fork if the soil is already loose) to dig over the area you will be sowing into (seed is sown thickly so a space of even 50cm square may be ample). Further fine the soil by donning your gardening gloves and crumbling it between your fingers. Mix in any compost, blood and bone, and general vegetable fertilizer you plan to include (leave out the lime if you intend growing tomatoes and other heat-loving vegetables in the same space over summer). Water the prepared ground so that it is dampened to a depth of 3-4 cm (it’s very important, at this cool time of year, not to saturate the soil).
Chicken microgreens should be sown in several shallow (10-12cm deep) rigid containers (keep the containers small enough so that, when filled with soil, they are easy to lift and carry to the chicken pen once the greens are ready). Prepare the soil for them in the same way you did for your own microgreens, then place them in the tunnelhouse to warm up.

Sowing
The usual rule when sowing seed (unless instructions specifically stipulate the seed should not be covered), is to cover the it in twice its depth of soil. However, because mesclun and chicken green mixes comprise a variety of seeds, you have to hedge you bets. To do this, sow all the seed to no more than the depth of the largest seed in the packet.
The soil covering seed needs to be as fine and as loose as possible. If you are concerned your soil is lumpy, rub it through a sieve first. Don’t be tempted to press down on the soil after sowing, as this will only compact the ground and make it harder for the smallest seed to push through. The seeds will need to be watered a little after sowing but not in such a way that you risk washing off the soil covering them. The best way to water newly sown seed is with a watering can. Start the flow from the spout BEFORE you water the seed patch, and stop the flow only AFTER you’ve moved the spout away.

Maintenance
If you and your chickens are craving fresh salad leaves, imagine how delighted the slugs and snails will be to discover them. Visit the tunnelhouse at night, with a torch, to check for pests, and remove them from the scene! If you choose to use a slug and snail bait, it is most important not to scatter it on your microgreen patch or boxes. You (and your chickens) will be harvesting the greens when the leaves are just a few centimetres high, and you don’t want to risk bait contaminating them. Instead, place the bait in shallow containers 5-10cm away from the germinating seed. Before harvesting, always check carefully for any dead or dying insects that may have made their way into the leaves after eating bait, and remove them.

Tips:
Harvest your human microgreen leaves, starting from when they are 5-6cm high. Use clean scissors to snip them into a sieve, and rinse them well before enjoying them as ingredients in a small salad, a sandwich, or scattered over pizza.

Leave a third of the growth on your human microgreens when harvesting, and many of the seedlings will carry on growing to produce a second or third harvest.

Prick out a few seedlings from your human microgreen mix, and plant them, in their own spot in the tunnel house, to grow on into full-sized leafy vegetables once the days start to warm up.

Deliver your chicken microgreens to your hens in the box the greens were grown in. Remove the box from the pen while there is still some leaf showing, and return it to the tunnel house. where the seedlings can grow on, ready to deliver the chooks another feast.

Once the boxes of chicken greens have been devoured completely by the hens, simply sow more chicken microgreens into the same soil, and cover lightly as you did first time around.

May- Growing Spring Bulbs

Tunnel House Techniques to Growing Spring Bulb Beauty!
The promise of spring bulb beauty and fragrance is something all gardeners hold onto through the darker, chillier days of winter. Some of us get it by planting bulbs in containers, and letting them strut their stuff on the deck. But many of us want our bulbs to bloom indoors where where their fragrance will fill the room. While it’s possible to do this by forcing bulbs to bloom in a narrow-necked container filled with water, the chances of repeat blooming the following year is very slim. You can also try planting a bulb in a pot and leaving it on a sunny window-sill to grow. In this case, however, your foliage is likely to be long and floppy, and the stem of the flower similarly so. However, if you’re smart, and know how to use your tunnel house to the max, you can coax gorgeous, light-foliaged, strong-stemmed bulbs into bloom well before spring even arrives, and enjoy them inside your home! What’s more, if you care for your bulbs wisely, they are very likely to flower for you again the following spring. Here’s how to work that spring bulb magic using your tunnel house:

‘Ground’ work
Growing medium
Your spring bulbs have a lot of work ahead of them – putting down roots, reaching for the light, growing foliage, and producing a flower. And they will be doing it all in the depths of winter. Give them the best possible start by growing them in a sterilised bulb or potting mix rather than your own heavy, damp, possibly fungal-contaminated garden soil.

Nutrients
Bulbs contain all the energy they require to produce this spring’s flower. But if they are to produce a flower next spring, they will need your help. That’s because their energy-gathering takes place the year before they flower. Bulbs gather energy for the following year from the sun, and from the soil nutrients in which they grow. They also (as they eventually dry off) gather energy by drawing down the nutrients stored in their leaves. To give bulbs the best chance of repeat flowering the following year, choose a growing medium which contains a slow-release fertilizer. If it doesn’t, add your own.

Containers
When choosing pots for your bulbs, select those that have at least one drainage hole in the base and which are either plastic, or terracotta with a glazed inner or outer surface. Using terracotta that isn’t glazed is inviting the growing medium to dry out too quickly, especially once the bulbs are brought inside. While you’re at it, choose containers that will compliment the colour of the flowers you are growing. Your pots can vary in depth according to the size of the bulbs you plan to grow.

Planting
Drainage

There is no need to cover the pot’s drainage hole with gravel. This is a myth, and simply creates less space for the growing medium. However, it is important to raise your pot a centimetre or two above ground level to assist with drainage (use sticks, brick, or pot feet to do this, while keeping the pots stable).

Depth
Bulbs have a ‘pointy’ end (from which their stem grows), and a ‘flatter’ end (from which their roots grow). In the pot, the pointy end faces up, and the flatter end faces down. As a general rule, bulbs require 2-3 times their own height of growing medium below them, and 1-2 times their height of growing medium above them. While outdoor grown bulbs require more spacing, container grown bulbs can be spaced just 1-2cm apart.

Methods
There are two planting methods for container grown bulbs. The first, is to plant a single layer of one species (such as daffodil), or a single layer of similarly-sized bulbs of different species (such as daffodil and hyacinth). The second method (which is especially useful if you have only a small space in your home to display your flowering bulbs) is to plant different species of bulbs in layers. Begin by planting (pointy end up) a layer of your largest bulbs (such as daffodils). Cover (and no more) the bulbs with growing medium. Next, plant a layer of medium-sized bulbs (such as tulips), and cover in the same way. Continue on with a layer (or two) of smaller bulbs (such as crocus, grape hyacinth, and freesia). Cover the last layer with growing medium to a depth that is twice the smaller bulb’s height. The top layer of bulbs with flower first, and as their blooms wane, the lower layers will take their place.

Watering
After you have planted your bulbs, water the growing medium until you see a little moisture escaping the drainage hole. Water again only when the top 2-3cm of growing medium has dried out.

Tunnel house magic
After planting your bulbs, move them into the warmth of your tunnel house to allow the growing medium to warm up. BUT, place them in a shady spot such as under solid shelves. If you don’t have a shady spot, create one with a small canopy of shade cloth. Providing the bulbs with tunnel house warmth, while also keeping them in the shade, will slow down stem and foliage growth while the bulbs put down a healthy root system. This well-developed root system will support nutrient gathering.
Once you spot the green tips of the bulbs emerging through the growing medium, move their container into the light, taking care to rotate the pot each day so that all bulbs have an equal share of light. Keep a watch for slugs and snails, and if necessary, visit the pots after dark, with a torch, to pick off the pests.
Although slow-release fertilizer will feed your bulbs steadily, you may like to treat your plants to an extra feed of high potassium liquid fertilizer when the green tips first appear (look for high potassium liquid feed in your garden centre).
As soon as you spot the developing flowers, bring your pot into your home and place it on a sunny window sill where you can watch the blooms develop.

Maintenance
Once your bulbs are indoors, provide their containers with saucers to collect any moisture, and continue to rotate the containers to ensure even light. You will find that it is now necessary to water the growing medium more frequently because of the warmth of the environment.
Once the flowers are spent, take your pot outside and place it under a sheltered hedge or shrub. When all the foliage has died completely down, remove the bulbs from the container, and place them in a cool, dry spot to dry off. Store them in paper bags, ready to plant again next spring.

Tip
Container grown bulbs that have been well fed in the previous year have a good chance of flowering again the following spring if grown in containers once again. However, many gardeners prefer to alternate bulb planting from year to year between garden and containers. This gives them an even greater chance of flowering success.

An over-heated room can sometimes cause blooms to become floppy. If this is the case, move the pot to a cooler spot for a few days, to recover.

Move your bulbs to a cool room at night to prolong flowering.

It’s seldom too late too plant bulbs in autumn, and even early winter. Look out for bulb sales suring these periods, and don’t shy away from purchasing sale bulbs that have alrady begun to show a growing tip. If you do buy these cheaper bulbs, however, bear in mind that they may not flower again as well next spring.

May- Cut into Cabbage this Winter!

Cut into Cabbage this Winter!
Who doesn’t love a sweet, tender cabbage in the middle of winter! Whether you stuff the leaves, finely slice them into a crisp coleslaw, or steam and smother them with black pepper and butter, a cabbage is a cool season treat we can’t do without. While winter cabbages will struggle on in the big outdoors, perfect, unchecked specimens from the tunnel house provide the biggest, tastiest returns. In fact, they can be so tender that even their out leaves can be used to make a meal! Growing cabbages isn’t difficult, but one of the biggest problems facing gardeners is what type of cabbage to grow at which time of year, so let’s clear up the confusion before we go any further!

Cabbages for all seasons
Cabbages are defined by the season in which they are harvested. For instance, a ‘spring cabbage’ isn’t planted in spring, it’s harvested in spring. Some cabbages are known as ‘all season’ cabbages, and can safely be planted at all times of the year with the possible exception of summer if you live in a very warm part of the country. Tunnel house cabbages are best saved for growing and harvesting in autumn and winter (because outside of these seasons, you’ll want your undercover space for growing heat-loving crops). That means you’ll be looking for ‘winter cabbage’ varieties, and among these, some of the best for tunnel houses are the ‘space saver’ and ‘mini’ cabbages (they come in both red and green). These smaller heading varieties make the best use of your limited space because they can be planted more closely together than larger heading varieties.

Seed-raising
It’s always best to sow your own cabbages from seed. In fact, any brassica (cabbage family plant) is best home-sown because to buy-in seedlings is to risk bringing into your garden the dreaded brassica disease ‘club root.’ However, if you live in a cooler part of the country, raising cabbage seedlings needs to start no later than mid-March, so if you don’t have cabbage seedlings on hand towards the end of autumn, you will need to head to a reliable source for those that you require.
To raise your own seedlings, fill individual-cell punnets with quality, commercial seed-raising mix. Water well and allow to drain thoroughly. Sow seeds, one to each cell, covering them with 4mm of mix. Germination takes place at around 23-24°C (a sunny window sill or warm room will provide this during warm days, but if conditions are cool, use a seed raising pad or pop your punnet, on a saucer, on top of your hot water cylinder until the seed germinates). Once seed has germinated, take the punnet into your tunnel house. Keep the mix damp but not moist, and protect the seedlings from pest attack with an appropriate bait (follow instructions on the container carefully), or by checking them each night with a torch, and removing nusiance
bugs. Once the seedlings have developed 3 true leaves (leaves that look like those on an adult plant), they are ready for transplanting in prepared tunnel house ground.

Ground work
Cabbages taste best when they grow rapidly in cool conditions, which is why your winter tunnel house environment is perfect for them. Provide the best growing medium by digging in 3-4 buckets of mature compost per half half square meter of ground, along with a scattering of sterilised animal manure pellets, and a sprinkling of blood and bone. Water the ground deeply (so that it is damp to at least the depth of a garden trowel. Leave it to drain over night.
While you are waiting, prepare a concentrated liquid feed by soaking together, for a week, in equal quantities, chopped seaweed (seaweed extract can be purchased from the garden centre if you cannot lay hands on kelp), and shredded comfrey leaves. Dilute your liquid feed at a rate of 1 to 4 for use as liquid manure feed.


Sowing and Transplanting

Gently tap the cabbage seedlings 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 planting pockets (30-40cm apart for space-saver cabbages and 50-60cm apart for full sized cabbages) 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
Keep the ground around the seedlings damp but not moist, and free of weeds. Water them with your liquid fertilizer one a week for the first 4 weeks of growth. Provide plenty of ventilation by opening two ventilation points during the day. Reduce to one (partially open) at night. Each sunny day, open the door to the tunnel house fully, and protect the entrance from birds and other animals with a screen door, or with netting held in place with clothes pegs. Close the door before the day cools down.

Tips:
When watering, do so around the base of the plants, and avoid wetting the leaves.

When harvesting, take your cabbages first from the middle of the patch, and then from between other cabbages. This helps provide as much airflow as possible around the remaining plants.

Take off any outer leaves that show signs of disease, as soon as you spot it.

Remove the stump of the cabbage after cutting it to prevent the chance of disease setting in to the cut.

If the unexpected happens and your cabbages begin to run to seed, harvest them in the early stages of this transition so they can still be used in the kitchen.

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).