November in the tunnelhouse

Welcome to Morrifield’s monthly garden guide where we go undercover to bring you the best tips and tasks for great greenhouse growing. Late spring sees undercover gardeners embarking on the marathon task of building up seedlings into strong plants that will see the season through, and produce a bumper crop on the way. By pampering, pruning, and protecting, we can all look forward to delicious produce from our heat-loving plants, and a season of undercover fun!

Morrifield’s Gardening Zones
Our long maritime country is filled with exciting microclimates. That means your gardening zone may be quite different to your neighbour’s, just a few kilometres away. Use our simple descriptions to help gauge which undercover zone sounds like you!

Zone 1 (Warm Winters, Hot Summers)
Zone 2 (Mild Winters, Hot Summers)
Zone 3 (Cold Winters, Mild Summers)
Zone 4 (Severe Winters, Hot Summers)

Top Tasks Around the Country

All zones

Tailor-made feeding

Tunnelhouse plants require specific feeding depending on their stage of development. At this time of year, quick results are required to help build up a plant’s foliage, and strengthen its stems. Fast nutrient uptake is best delivered via liquid feeds, and fertilizer (organic or inorganic) should favour a slightly higher ratio of nitrogen to phosphorus and potassium. Organic growers using animal manure to provide this, should make sure it is at least a year old. If it’s fresher, there is a risk that it will damage your plants’ roots and foliage. If in doubt about the age of manure, choose horse manure which is less nitrogen high, and therefore unlikely to cause problems, even when relatively fresh.

Zones1 & 2

Mulching musts

The season is hotting up, and soil temperatures are looking good. That’s your signal to bring in the mulch. When young seedlings go into the tunnel house, mulch can prevent the sun reaching the soil, and slow down the warming up of the ground. But from now on, the increasing warmth will evaporate moisture from the ground – a problem for two reasons. Firstly, all that moisture goes into the greenhouse, increasing humidity and inviting fungus to take up residence. Secondly, shallow-rooted plants face drying out before you can get round to the next watering cycle. Mulch will help reduce evaporation but before you invest in it, be sure to check it hasn’t been exposed to glyphosate. This chemicalt, even in minute quantities, is highly toxic to many plants, especially tomatoes. Once tomato plants are exposed to it, there is no way to save them.

Two stems are best!

Nipping out laterals on indeterminate (vine-varieties) of non-grafted tomato plants is essential if we want our plants to produce as quickly as possible, and put their energy into flower and fruit production rather than foliage. And November is the time to be doing this. But here’s the thing: research shows that we get a 10-15% increase in harvest from greenhouse tomatoes if we allow two stems to grow from the one vine instead of one. So, as you de-lateral, consider leaving one side branch on the plant, close to the base of the vine, to grow into a second stem.

Spacing

The traditional advice is to space greenhouse tomato plants 45-50cm apart. But that’s not necessarily the best advice for you! If you prefer smaller tomatoes, but lots of them, plant your seedlings closer together. If you want larger tomatoes, and fewer of them, stick to the traditional spacing. Smaller tomatoes are desirable for salads or if your household consists of just one or two people. On the other hand, large fruit are useful for stuffing or saucing. Whichever way you look at it, it’s good to know you can have some control over your harvest.

Zones 3 & 4

Keep them cosy!

Late spring is the time to double the value of your undercover growing space. Most growers will by now have their heat-loving seedlings planted out in their tunnelhouses, but because these plants are still babies, there’s loads of space in between them – space which can hold heat-lovers that can manage life outdoors once the world warms up. We’re talking pumpkins, zucchini, outdoor tomatoes, pepino, Cape gooseberry, and the like. Grow these plants in disposable bags filled with rich, free-draining compost (disposable bags can include hessian sacks, past-their-best fabric supermarket bags, plastic grow bags, and old compost bags with holes cut in their base). Place the bags between your tunnelhouse seedlings. By the time your true tunnelhouse plants require more space, the temperature outside will have warmed up and your grow-bag plants can be moved outside. Either leave them to grow on in their bags or, better still, dig a hole for them in a sunny spot in the garden. Pop the plant, bag and all, into the hole. Carefully slit the bag open and slid it out from around the plant – there will be little root disturbance, and the plant will have a head start on any others sown outdoors! 

Head start!

If you live in one of the coldest parts of the country, it can be frustrating to know that others have planted out their tunnelhouse while your seedlings are still 2cm high on the window ledge! But greenhouse hydroponics can give you the head start you’re looking for. There are simple beginners kits available at garden centres to get you started, or you can go DIY with your own creation. By introducing a water-heating system into the equation (and raising your growing solution to 16-18°C) you can extend your seasons even further. Factor in thermostatic control, and you also won’t be caught out with a late frost. Some cold-region greenhouse hydroponic growers report that they are eating their tomatoes in December. Now, that’s inspiring!

Don’t cook me too soon!

While summer is still on its way, undercover growers can get a little over-excited about the heat being generated in their tunnelhouses. Take advantage of it, but remember that, even in spring, temperatures in the greenhouse can quickly rise to unhelpful levels if ventilation isn’t adequate. Once temperatures rise above 27°C (and a greenhouse thermometer will help you gauge this), many greenhouse plants begin to suffer. So, make it a routine to open ventilation as soon as you get out of bed in the morning. If this isn’t practical, and you have the means, think about installing additional ventilation. Early morning is the time of day when birds are actively feeding, so be sure to have a screen door or net covering on the door of your greenhouse to keep them out. Leaving vents open during the warmer months will not affect your plants. Just remember to shut vents and other ventilation down in case of an unexpected cold snap or storm.

Sow me undercover now 

All zones 

Basil, cucumber, chilli, ginger, lemongrass, turmeric, tomato.

Zone 3 

Cape gooseberry, cucumber, sweetcorn, dwarf beans, lettuce, pumpkin, zucchini.

Zone 4

As for Zone 3 and also including: annual flowers, chilli, cucumber, brassica, leeks, spring onion, potato, tomato, zucchini.

Transplant me undercover now 

Zones 1, 2 & 3: aubergine, capsicum, chilli, cucumber, melon, passionfruit, tomato, zucchini.

Zones 3 & 4

Citrus, grape

Zone 4: lettuce, spring onion, zucchini.

News and views

OCTOBER IN THE TUNNELHOUSE – All SYSTEMS GO!

October in the tunnelhouse

Welcome to Morrifield’s monthly garden guide where we go undercover to bring you the best tips and tasks for great greenhouse growing. Mid-spring is a period of intense juggling as many of us make the big switch from harvesting cool season crops, to getting the heat-lovers into their greenhouse beds. But along with all that, we still need to provide undercover space for tender seedlings that will eventually live outdoors all summer. It’s enough to make a greenhouse grower feel like they’re quick-changing scenery for a theatrical production. Good luck!

Morrifield’s Gardening Zones
Our long maritime country is filled with exciting microclimates. That means your gardening zone may be quite different to your neighbour’s, just a few kilometres away. Use our simple descriptions to help gauge which undercover zone sounds like you!

Zone 1 (Warm Winters, Hot Summers)
Zone 2 (Mild Winters, Hot Summers)
Zone 3 (Cold Winters, Mild Summers)
Zone 4 (Severe Winters, Hot Summers)

Top Tasks Around the Country

All zones

Planting for pollinators

Many of our greenhouse plants (such as tomato, capsicum and aubergine) are self-pollinating. This means that when the plants move (in a breeze, for example) the pollen falls down through the foliage from flower to flower, fertilising as it goes. Other greenhouse plants (such as the strawberry, and most cucumber), require insects to pollinate them. In both cases, however, it pays to lure pollinating insects into the greenhouse because the buzzing of insects’ wings helps move pollen about in an environment where little wind is available. Bumble bees are especially helpful pollinators because they fly in cooler weather so they are busier than honey bees, working from spring to autumn and from earlier in the morning until later in the evening. Lure pollinators (especially bumble bees) into the greenhouse by planting pots of dwarf comfrey, borage, larkspur, sunflowers, phacelia, lavender and salvia. When in bloom, move these plants to the door, and even inside the greenhouse as an attractant.

Soil structure broadfork

The more we learn about microbes in the soil, the more we understand how essential fungi are to the health of our plants. However, whenever we dig in the soil (and this includes in our greenhouses), we disturb, and often destroy, the fragile mycelium threads of fungi. Better by far, is to simply loosen the soil without turning it over, and to then add a top layer of rich, weed-free compost that is enriched with natural manures. A broadfork or wide garden fork is the tool to use to help loosen your greenhouse bed without destroying its structure. Simply push it into the ground to its full depth, and work it back and forwards without turning the soil over.

Reestablishing the fungi

It happens to the best of us – one minute our greenhouse is thriving, and the next, it’s been ravaged by fungal disease. Fungal disease sets up home in poorly ventilated greenhouses, and when it does, it drops spores that reinfect plants the following season. While most of us manage a fungal hit organically, sometimes the devastation is so all-encompassing that we seek out chemical alternatives. When we do treat the ground with an approved fungicide, we usually take out our beneficial soil fungi at the same time. If this is your situation, consider using mycorrhizal fungi granules to reestablish your good guys. Follow the instructions carefully as there may be a time lapse between fungicidal treatments and the application of the granules.

Zones1 & 2

Moving home – easy does it!

October can bring surprisingly warm weather but it can also take it’s time in heating up the ground outdoors. If your night time temperatures are still below 13°C, and soil temperatures outdoors aren’t moving above 18°C, keep your heat lovers (such as aubergines, tomatoes, melons, peppers, basil, and cucumbers) tucked up in the greenhouse. Feed them regularly so they don’t lose condition and begin to attract pest insects, and if necessary, consider repotting them before the big move outdoors.

The big cover-up

Heat can be a killer in the greenhouse, especially when your undercover space is fully exposed to the sun. Don’t leave it too late to assemble your sun protection. The single most important option when considering buying a greenhouse or owning a greenhouse/ tunnelhouse is to provide as much airflow/ ventilation as possible during these warmer months. Morrifield can provide back door and window options in new models and these can also be retrofitted to exisiting models as well. Don’t forget our Screen Door options also, these are a fantastic way to keep most of the birds/ bugs and pests out but still offer ventilation.

Morrifield Screen Door kits are ideal for the warmer months of the year. They allow you to keep the tunnlehouse ventilated but still let through the airflow. Great for helping to keep out the pests!

If you dont have any ventilation in your tunnlehouse, Window and door kits are available to retrofit and help with ventilation and airflow

A great alternative  is to have a shade cloth cover. Make your own by purchasing the fabric by the meter,  Remember to allow extra length as it will need to be held down in windy situations. Generally about 5.2 m lengths is ample to fit over the entire tunnelhouse. You can use a wooden batten to roll and fix the material then screw to the timber base. If you don’t want to leave the shade cloth on all summer,  it so that it can be and taken off, as required.

If you are growing taller plants outdoors (such as corn or runner beans) consider planting them so that, as they gain height, they shelter the greenhouse from the heat of the sun. When they mature in autumn, they can be cut down so that you have the sun, again, to heat the greenhouse over winter.

Zones 3 & 4

Beautiful basils

One of the joys of a greenhouse is the ability to grow basil in decent quantities (think pesto, pizza toppings, and fabulous flavour in salads). While it’s still too cool for basil in the greenhouse in October, it can be raised on a sunny window ledge indoors, then transplanted into the greenhouse in November or December. Basil doesn’t enjoy root disturbance, so sow into a good sized pot which can be upended, holus-bolus, into a prepared hole in the greenhouse bed. There are a whole range of basils to choose from, so why not make it your specialty crop this summer.

Green with Envy

Asparagus is the talk of the town in September and October, yet many of us miss out on our own harvest because we don’t remember to plant it in time (September through to December is the range to plant it). Asparagus doesn’t enjoy wet, cold ground, so if you’re in a damper, colder part of the country, the greenhouse can be the perfect situation for this seasonal treat. Asparagus is a perennial, and it’s foliage does need to grow on after harvest, to feed the plant for the following season. This means you’ll need to devote a section of your precious greenhouse space to its cultivation – but who can resist those green spears on buttered toast! Source your asparagus crowns now, while you think of it, and start digging the richness into this hungry plant’s new bed.

Sow me undercover now

Zones 1 and 2

In seed trays or pots: annual flowers, lettuce, zucchini. In ground: basil, cucumber.

Zone 3

In seed trays or pots: annual flowers, basil, beans, brassica, celeriac, cucumber, corn, lettuce, leeks, zucchini, spring onion, potato.

Zone 4

(In seed trays or pots): aubergine, capsicum, chilly, cucumber, tomato, zucchini.

Transplant me undercover now 

Zones 1 & 2: aubergine, capsicum, chilly, cucumber, melon, tomato, zucchini.

Zone 3 & 4: asparagus, dwarf beans, spring onion, zucchini.

News and views

September in the tunnelhouse

Welcome to Morrifield’s monthly garden guide where we go undercover to bring you the best tips and tasks for great greenhouse growing. At last, spring has arrived, and the busiest month of the season is calling us into the tunnelhouse. Wherever you are in the country, there’s a whole host of fun to be hand, and new growing opportunities to look forward to!

Morrifield’s Gardening Zones
Our long maritime country is filled with exciting microclimates. That means your gardening zone may be quite different to your neighbour’s, just a few kilometres away. Use our simple descriptions to help gauge which undercover zone sounds like you!

Zone 1 (Warm Winters, Hot Summers)
Zone 2 (Mild Winters, Hot Summers)
Zone 3 (Cold Winters, Mild Summers)
Zone 4 (Severe Winters, Hot Summers)

Top Tasks Around the Country

All Zones

Trust home grown

It can seem so much simpler to head to the garden centre for your greenhouse seedlings rather than grow your own. But this shortcut soon turns to custard. That’s because many store-bought seedlings are regularly sprayed to rid them of pest insect infestations. Once you get the seedlings home (especially if you are an organic grower), insects eggs on the underside of leaves soon hatch, and the population takes off! Play it safe, and grow your own plants. If you must buy from the garden centre, take along a magnifying glass to check for signs of insects and eggs, before you purchase.

Tap into tomatoes!

Growers everywhere are starting to raise their own tomato seedlings. If you’re looking at a packet of your favourite tomato seed, and wondering if it’s too old to germinate, bear this in mind: tomato seed remains viable for longer than many other seeds. Provided it’s been stored in a cool, dry place (preferably sealed in foil), an encouraging number of the seeds seed will still germinate. Give them the best start in life by sowing them in individual containers of fine seed raising mix, and placing these on a germinating heat pad. Sow the seed more thickly than you would normally (5-6 seed to a container instead of 1 or 2).

Screen saver

Before the weather grows warmer, giver serious thought to fitting a screen to your greenhouse (if you have a Morrifield tunnelhouse, the screen can be retro-fitted). Screens allow for essential ventilation without the risk of birds entering the greenhouse to dig up plants and attack ripening fruit. A screen will also exclude pest insects, prevent beneficial predator insects from escaping (beneficial insects can be purchased from Bioforce), provide shelter from wind, and keep out pesky cats.

Fire up the feed!

Rapidly growing plants thrive on readily available nutrients fed in solution form. While you can always head to the garden centre for liquid fertilizer, it’s more economical to make your own. Best of all, DIY solutions can be tailor made to suit the edibles you’re growing! Start with the basics by soaking 1 bucket of compost, 1/2 a bucket of nettles, and ¼ of a bucket of wel-rotted animal manure in 4 buckets of water, for 2-3 days. Stir vigorously 2-3 times during this period. Next, scoop out 4 individual buckets of soaking liquid. To make a tomato-specific tonic, add chopped kelp and a cup of non-toxic, untreated, unpainted firewood ash.  For an aubergine feed, add a handful of fish meal to the bucket. Make a cucumber cocktail by stirring a handful of blood and bone into a bucket of basic mix. For a capsicum boost, add the works with extra well rotted animal manure, kelp and torn comfrey leaves. Leave your buckets of goodies to soak for at least a week before straining off the liquid and bottling in screw-top containers. Feed your growing plants every week to ten days throughout the growing season.

Zone 3 & 4

Early birds

Most cool-climate zucchini growers plant their seedlings outdoors from October through to December. However, an early spring start for these tender treats is possible when you sow seed into bucket-sized bags of rich potting mix, and grow them on in the greenhouse. A zucchini’s delicate root system means the plant doesn’t like to be disturbed. However, but once the weather has warmed up outside, the bag can placed in a planting hole, then carefully split open with scissors to gently release the zucchini with minimal disturbance. Tip: choose jute bags rather than black plastic grow bags – they can be popped into the compost when you’ve finished with them, or you can recycle the black plastic bags.

Hedging your bets

Cool climate gardeners are among the keenest of tunnelhouse growers, forever ‘testing the limits’ as to what can be successful in their undercover environment. If you want to experiment, consider growing new plants in containers, even though you may be growing your regular heat-lovers in-ground. That way, if there simply isn’t enough heat for your experimental plants to thrive, they can be easily removed without disturbing the roots of their neighbours. And a quick growing tomato or cucumber can be popped in to fill the space.

While you wait

Waiting for the world to warm up can be disheartening, but not more so than popping your heat-loving plants into the greenhouse while it’s still too cold for them. Cold, struggling plants are vulnerable to disease, and are unable to take up the nutrients you’ve supplied them with. While you wait for the heat to arrive, fill your greenhouse with fast-growing Asian and microgreens. Any that haven’t been used up by the time the heat-lovers are ready to be planted, can be dug back into the ground to help feed the bed.

A staged show

The greenhouse is a goldmine for cool climate growers when they use their September undercover space to raise salad greens and brassica seedlings. But remember – these little plants all require their fair share of light. Staged (or ‘terraced’) shelving is the way to help it happen. If you don’t want to purchase staged shelving, make your own using untreated, unpainted boards and bricks. Just make sure the structure is stable so that it doesn’t fall and damage the sides of the greenhouse.

Rooted in warmth

No one wants their greenhouse overrun with sprawling vines, yet, in a cooler climate, heat loving plants such as melon, kumara, kumikumi, and pumpkin, often do best when planted indoors. The solution is simple: start your vine off in a corner of the greenhouse, then tunnel under in one or two places to make a small escape route for the vine to grow through. It can then grow on, into the outdoors while its roots benefit from the warmth of the greenhouse soil.

Sow me undercover now 

Zones 1 and 2

Aubergine, basil, capsicum, chilli, cucumber, lettuce, melon, zucchini, tomato (all summer varieties).

Zone 3 and 4

In the greenhouse (in-ground): fast-growing microgreens, ‘Tasty Tendrils’ peas, potatoes and yakon (in bags to be shifted outdoors, later). In the greenhouse (in seed trays or individual containers): baby carrots, brassica, lettuce, silver beet, spinach, spring onion. Indoors on germination heat pads or a sunny window ledge: basil capsicum, chilli, tomato,  zucchini.

Transplant me undercover now 

Zones 1 & 2: lettuce, turmeric, zucchini

Zone 3: early tomato 

News and views

Not only is your tunnelhouse great for fruit and Vegetables, we have many customers growing flowers. Jen from Oxford in North Canterbury uses her Tunnelhouse for her flower business @theflowerlabnz and specialises in dried flowers. Her tunnelhouse will be brimming with Spring goodies!

Thanks Jen for the photos

August in the Greenhouse!

Welcome to Morrifield’s monthly garden guide where we go undercover to bring you the best tips and tasks for great greenhouse growing. While wild weather continues in many parts of the country, spring is just around the corner, and early bird greenhouse growers are already preparing for it!

Morrifield’s Gardening Zones
Our long maritime country is filled with exciting microclimates. That means your gardening zone may be quite different to your neighbour’s’ just a few kilometres away. Use our simple descriptions to help gauge which undercover zone sounds like you!

Zone 1 (Warm Winters, Hot Summers)
Zone 2 (Mild Winters, Hot Summers)
Zone 3 (Cold Winters, Mild Summers)
Zone 4 (Severe Winters, Hot Summers)

Top Tasks Around the Country

All Zones

Prepare supports

Don’t leave it until your greenhouse plants are in place before installing supports – they won’t thank you for the disturbance, or for having their roots compressed as you tread on the ground. If you’re growing climbers, such as cucumber and vine tomatoes, your greenhouse purlins may be strong enough to take the weight of fruit-bearing plants, in which case you can tie support twine to them. (The purlins of a Morrifield tunnelhouse are suitable for this purpose.) Always choose light, rather than dark twine, so that heat is not concentrated where the twine meets the tunnelhouse skin (something which can reduce the life of the covering).

Where necessary, create your own ‘purlins’ by running lengths of number 8 wire below the ‘ceiling’ of your greenhouse, and attaching them to the frame if you consider it strong enough. If your greenhouse is covered in plastic (or a similar heat-sensitive material) be sure to keep the wire ‘purlins’ well away from this in case they heat up and melt surfaces. Tip: to cut number 8 wire, use a sharp file to create a groove. Then, work the wire, either side of the groove, back and forwards until it snaps.

Stakes can be used to support taller plants in the greenhouse. Plastic-coated metal stakes are strong, easy to push into the ground, and should have no sharp edges that could damage the skin of your structure. Bamboo stakes, especially if grown locally or on your own property, are a sustainable option. If you plan to grow determinate (bush tomatoes), cages will prevent sprawl, and hold plants off the damp ground, reducing the chance of fungal disease developing.

Recycle clean-up

There’s every reason in the world to recycle greenhouse infrastructure such as stakes, cages, and inorganic strings and ties (don’t rely on organic strings from a previous year – they will not be strong enough to support plants for another season). However, if reusing materials, don some protective, waterproof gloves, and give your equipment and ties a good wash down with household bleach (diluted according to instructions). This will help kill off fungal spores. While you’re at it, wipe your sanitising mix over any irrigation equipment you have in the greenhouse.

Install irrigation

Unless you are growing on a large scale, or don’t have the ability to wield a watering can, hand watering at ground level is always best. It puts you firmly in touch with the state of your soil, avoids over watering, and provides an opportunity to check on plants, pests and disease, as you work. However, irrigation does have its uses, especially if you plan to take extended breaks away from home during the growing season. When choosing greenhouse irrigation, always opt for a system which delivers moisture at ground level. Overhead sprinklers are a recipe for disaster in the greenhouse, wetting foliage which should remain dry, and inviting in disease that comes with high humidity and damp conditions.

For those who are not on mains pressure, or who don’t have enough water pressure in their domestic system to operate an irrigation system, check out the submersible Aqua One pump available from Mega Mire 10. It can lift water from a barrel close to the greenhouse, and deliver it to plants).

While it’s best to personally check on soil moisture levels before watering a greenhouse, this isn’t always an option. In which case, an automatic timer system is also a worthwhile investment.

Zones 1 & 2

Start seed raising!

Don’t leave it too late to raise your greenhouse seedlings – if you do, you’ll be heading to the garden centre, and paying premium prices for plants you could have grown yourself. One of the best purchases a thrifty greenhouse grower can make, is a propagating board or pad. These start at around $35, and they not only hurry along germination, but give seedlings the best start in life. Team your propagator with a garden thermometer to help you gauge the perfect temperature for germination. Cucumber seed germinates best when soil temperature is between 20 and 30°C. Tomato seeds prefer 21-23°C, and capsicum, chilli and aubergine germinate when soil is around 27-32°C. To adjust the soil temperature of seeds on a propagator, use a cake cooler to raise containers off the heat source. Alternatively, place a clear container over pots of seed to trap in extra warmth. Be aware that soil temperature changes throughout the day according to how strongly the sun is shining, so use your thermometer, often, to check.

Zones 3 & 4

Chop, drop & dig!

Cover crops are the natural way to fertilise your greenhouse soil, and August is the month to dig them back into the ground. If you grew mustard greens or broad beans, you’ve doubled the potential for good. Mustard greens exude sulphur-containing compounds which help cleanse the greenhouse soil of pathogens. Broad beans plants harvest nitrogen from the air, and deliver it back to the soil as plant material breaks down. Use shears to cut down and snip up your cover crops. Use a sharp spade to slice up roots. Mix everything into the soil, and water the ground thoroughly to speed up decay (water every couple of days for a week if the weather is warm and the soil is drying out). Your cover crop will break down in 2-4 weeks depending on weather conditions.

Welcome in the cold!

August is the coldest month in many parts of the country, and while we want all the heat we can get in the greenhouse at this time of year, chilly temperatures are also an opportunity to naturally kill off over-wintering pest bugs. Your winter veggies won’t mind if you open the greenhouse doors and windows on warmer days (just be sure to close everything up again before the sun goes down). And a fresh breeze will send the white fly packing in no time at all!

Hello, hydroponics!

In colder parts of the country, the wait for greenhouse soil to warm up, can be frustrating. One way to get a head start is to set aside part (or all) of your greenhouse for hydroponic growing. When combined with a water heating system, hydroponics means your the roots of your plants can be growing in temperatures of 16-18°C on a chilly day! With a thermostatically controlled system, the warmth continues through the night, encouraging rapid growth. By sowing the seed of cool climate tomato varieties in winter, and growing the resulting seedlings, hydroponically, in the greenhouse, you can aspire to fresh tomatoes in December! If you plan to dedicate your greenhouse to hydroponics, consider designing its floor so it has a 1:40 rise. This will help water drain from growing troughs.

Going green

It’s a myth that garlic must be planted in the depths of winter. In fact, current thought is that it should be sown at the best time of year to avoid the now widespread allium rust. In cold regions, garlic is often best sown in September or even October. While you wait, break up cloves, and place them in a container in the greenhouse where the light will encourage sprouting. Alternatively sow the cloves into individual containers of potting mix, and place these in the greenhouse to give this valuable crop an early start.

Sow me undercover now

Zones 1 and 2

Directly into the ground: cool season microgreens,  radish, spring onion, ‘Tasty Tendrils’ peas, peas (all other varieties),

In seed trays or bags for transplanting or moving outdoors later: ‘Alboran’ tomato, broccoli, cabbage, cauli, rocket, silver beet, spinach, peas (all varieties), potato, yakon.

Zone 3 and 4

Directly into the ground: Leafy Asian greens (such as Chinese broccoli ‘Gai Lan’, mibuna, mizuna, pak choi, and tat soi), cool season microgreens, rocket, spring onions, strawberries, ‘Tasty Tendrils’ peas.

In seed trays or bags for transplanting or moving outdoors later: potato, yakon.

Transplant me undercover now

Zones 1, 2 & 3: kale, leafy Asian greens, rocket, silver beet, broad beans.

Zones 4: ‘Alboran’ tomatoes, lettuce, spring onion, spinach, microgreens.

News and views

Morrifield tunnelhouse sits 430 metres above sea level, near Fairlie. After a huge winter snow storm it was covered in approximately 1 metre of snow! A few days later, gales of around 130 to 140km/h lashed the tunnelhouse – but the structure is still in good shape!

 Biggest snow in 50 years in Kingston 

Snow Problem!

July in the Greenhouse!

Welcome to Morrifeld’s monthly garden guide where we go undercover to bring you the best tips and tasks for great greenhouse growing! Don’t you just love a mid-winter greenhouse! No matter what the weather is doing outside, your undercover plants remain lush and protected, and grow on regardless. What’s more, harvesting is a breeze – no need to don the raincoat and gummies, and heading out into the mud!

Morrifield’s Gardening Zones
Our long maritime country is filled with exciting microclimates. That means your gardening zone may be quite different to your neighbour’s’ just a few kilometers away. Use our simple descriptions to help gauge which undercover zone sounds like you!

Zone 1 (Warm Winters, Hot Summers)
Zone 2 (Mild Winters, Hot Summers)
Zone 3 (Cold Winters, Mild Summers)
Zone 4 (Severe Winters, Hot Summers)

Top Tasks Around the Country

All Zones

Test drive your commercial compost

If you’re nervous about using commercial compost mixes, we don’t blame you. Over the last 2-3 years, there have been horror stories up and down the country about summer greenhouse vegetable plants collapsing and dying – with many concerned growers pointing the finger at commercial compost as the culprit. If you’re concerned that your new season compost mix may be tainted with the likes of Glyphosate, buy it in now, and test drive it before spring (it can be stored in bags or under a taupaulin until required). To test, source tomato seedlings (or raise your own indoors if you can’t find any at the garden centre), and plant them in the mix you intend to use. Tomato seedlings are highly susceptible to Glyphosate residue so by the time your actual spring seedlings are ready to be planted out, you can reasonably confident about whether the mix you intend using is safe (or not). Tip – just because the mix you test is safe, don’t rely on your next load to be the same – ingredients can differ over time.

Sow your pollinator-plants now!

Flowering plants which attract insect pollinators into the greenhouse are so important. Save yourself dollars by sowing your own in the greenhouse right now. Come mid spring, they’ll be ready to plant in pots which can placed directly outside the door of the greenhouse where they are sure to lure in the good guys. Borage is a favourite with the bumbles. Calendula is hardy (it will flower right through winter in even the coldest places, and the honey bees love it!). Lavender is long-lasting, and doesn’t require a great deal of water in summer. For an early and long lasting pollinator-attractant, grow tree lucerne. It’s so easy to germinate!

Cuttings cost nothing!

There’s still time to take hard wood cuttings from your shrubs, to grow new plants from them. Choose mature, slender, woody pieces of stem that are around 25cm long. Snip them off your shrub, dip the cut ends in rooting hormone, and push them up to the half way mark in potting mix. (Rooting hormone is available from garden centres – or you can make your own by boiling half a cup of willow bark in a cup of water for 20 minutes, and cooling it thoroughly before using)

Pick a path

Winter is the best time to create a greenhouse path. If you’re not a ‘straight lines’ kind of person, go for a winding path – there are no rules, other than to create as much growing space as possible. If you live in a cold part of the country, choose a material that will absorb heat by day, and return it to the greenhouse at night. Dark gravel chip or rough-surfaced concrete pavers work well (some people opt for brick, but this can become slippery when wet, especially when it gathers algae). If you live in a hot part of the country, choose a light coloured chip, or crushed white shell (but take care – shell can be sharp on the feet). Light coloured material will reflect the heat back out of the greenhouse. Whatever you use, be sure to create an edging to hold back the soil, and always lay weed mat under your paving material.

Totara posts were layed as the pathway in this tunnelhouse

Photo credit- Katie-Jean

Undercover food forests

Diversity creates a healthy undercover environment, which is why it pays to introduce as many different plants as you are able into your greenhouse. Ornamental and perfumed plants will lure in pollinators, insectivorous plants will help cull aphids and greenfly (try hanging a pitcher plant from the roof of your greenhouse to catch these pests), nitrogen fixers, such as crimson clover, provide a living mulch, and plants such as dwarf comfrey help pull micronutrients into the root zone of your edible plants. There is every reason not to grow a monoculture in your greenhouse!

Photo credit- Lauren Moses in Dunedin uses her tunnelhouse as an undercover food forest

Order your seedlings – and be adventurous!

It’s time to put your feet up, and reach for the seed catalogue! There are so many new varieties of tomatoes, capsicum and chilli to choose from, so let your imagination run wild. But don’t stop there because a greenhouse offers the opportunity to sow exotic plants you may have only ever seen in a National Geographic magazine! Crops like millet, rice and soybean, and aromatics such as peppercorns, fenugreek, cardamom, cumin and vanilla bean bring a new dimension to your greenhouse. Be daring as you plan for the new growing season!

Set the timer

One of the most difficult aspects of greenhouse growing, is knowing exactly when to sow seeds. After all, you don’t want seedlings spending too long in their pots and becoming root bound and leggy before they go in the ground. On the other hand, what could be worse that planting out your seedlings too soon, only to have them hit by an intimidating bout of freezing weather! The secret to success is simple maths! Begin by checking out the date of the last frost frost for the year in your locality (a site such as Weather Spark can help with this). Next, make a Google check to see how long your chosen plant will take to grow from seed to transplanting stage. If, for example, it’s 6 weeks, then you will need to sow seed 6 weeks before the last frost in your region. This is a guide only, but it’s a place to start!

Zones 1 & 2

Oh, baby!

Yippee – we’re past the shortest day of the year! But that doesn’t leave a lot of time for newly sown or transplanted seedlings to mature before the heat-lovers go in the ground. That’s why, from now on, it pays to choose compact and mini varieties for the greenhouse. These little beauties are smaller than their big cousins so they mature more quickly. Even better, they don’t take up so much space so you can cram’m in! For a great choice in compact and mini veg head to Egmont Seeds for the likes of Beetroot ‘Bonny Baby’ (approximately 75 days to maturity), Broccoli ‘Mighty Mini F1 Hybrid (90 days), Cabbage ‘Ranfurly Mini F1 Hybrid’ (75 days), and Cauliflower ‘Majestic Mini F1 Hybrid’ (90 days). If you’re a Kings Seeds fan, check out their compact varieties, as well. And unless you live in one of the coldest parts of the country, sow a sprinkle of baby carrot seed while you’re at it.

Zones 3 & 4

It’s a wrap

A greenhouse will protect most plants from winter cold – but not necessarily if you live in a severe climate. If frost and snow are heavy (or worse – prolonged), take extra precautions with your undercover plants by draping them loosely in one (or two, if necessary) layers of light frost cloth. Woody potted shrubs (such as citrus and Federation Daisy) can be wrapped in a thicker covering of bubble wrap (just remember to leave a space at the top and bottom of the plant for air to circulate). Always be aware that a brief period of unseasonably warm weather can arrive, even in winter, and unwrap plants during the day if this seems a possibility.

Move the Mulch

Help your winter greenhouse soil to dry out and warm up during the day, by pulling back the mulch from the soil. Stack it in one corner if there is space, or bag it up and remove it until it is required again in summer to retain moisture and suppress weeds. Removing mulch also exposes over-wintering pests, and the eggs of snails and slugs.

Sow me undercover now 

Zones 1 and 2 Directly into the ground: baby varieties of brassica and beetroot, carrot, lettuce, garlic, microgreens, parsley, radish, spring onion. In seed trays or bags for transplanting or moving outdoors later: broccoli, cabbage, cauli, chives, Florence fennel, lettuce, rocket, silver beet, parcel, perpetual spinach beet, potato, New Zealand spinach. 

Zone 3 and 4 Directly into the ground: Leafy Asian greens (such as Chinese broccoli ‘Gai Lan’, mibuna, mizuna, pak choi, and tat soi), cool season microgreens, spring onions, ‘Tasty Tendrils’ peas. In bags for transplanting or moving outdoors later: potato.

Transplant me undercover now

Zones 1, 2 & 3: Compact and mini varieties of: broccoli, cabbage, and cauli. Kale, leafy Asian greens, lettuce, hybrid spinach, rocket, silver beet.  

Zones 4: Silver beet, celery, kale. 

News and views

Lauren Moses of Dunedin, uses her tunnelhouse as an indoor food forest, growing a variety of heat loving plants including a container-grown Banana plant which she brings indoors for Winter. Thats a huge achievement in a Southern city!

Photo credit-Lauren Moses, Dunedin

June in the Tunnelhouse!
Welcome to Morrifeld’s monthly garden guide where we go undercover to bring you the best tips and tasks for great greenhouse growing! Winter has arrived at last – and with a vengeance in many parts of the country. How we care for our greenhouse in the coldest season, and how we harvest the produce it grows, are both crucial this month. However, there’s always room for rest and relaxation – and if you take the time to give your greenhouse a makeover, it can can provide you with that, too!

Morrifield’s Gardening Zones

Our long maritime country is filled with exciting microclimates.
That means your gardening zone may be quite different to your neighbour’s’ just a few kilometres away. Use our simple descriptions to help gauge which undercover zone sounds like you!

Zone 1 (Warm Winters, Hot Summers)
Zone 2 (Mild Winters, Hot Summers)
Zone 3 (Cold Winters, Mild Summers)
Zone 4 (Severe Winters, Hot Summers)

Top Tasks Around the Country
All zones
Keep ’em coming!
If you planted out your greenhouse in autumn, chances are that you’re now looking at healthy salad greens and thriving brassica, tender celery and tasty herbs. But that pristine look that green house veggies exude won’t last long if disease sets. Disease enters a plant through frays or tears in leaf and stem tissue, which is why it’s almost always best to use your fingers, rather than a knife, when you harvest. Slide your fingers right down to the base of leaves and stems to snap them off cleanly. If you do harvest an entire head (such as in the case of a cauli or cabbage), pull the whole plant out of the ground – don’t leave the stem in the soil to attract fungal disease and rot.

Rotate!
Some growers will already be thinking about new sowings and transplantings. Treat your greenhouse as you would your garden, and keep rotating different families of veggies (brassica, especially, should never be planted in the same place twice – and that includes ‘soil-cleansing’ brassica such as hot mustard greens). Cover crops also need to be rotated.

Raising ’em right!
If you’re winter greenhouse beds are in-ground (rather than raised), soil temperatures can still be chilly. That’s why you might want to consider growing in containers over the coldest months, or even into straw bales. Raised beds (of any sort) become warmer because they are not in contact with the sub soil, and also because they drain more readily. If you decide to use straw bales to plant into, you have the added advantage of a straw mulch or soil addition when you’ve finished with them in spring. Simply remove the twine holding the bale together, and scatter or dig in the straw. For a guide to planting into straw bales, check  the link below

https://joegardener.com/podcast/gardening-in-straw-bales/

Bug orff!
Winter is nature’s ways of taking care of garden pest bugs such as aphids, shield bugs and whitefly – it zaps all but a hidden few with icy conditions. However, these pests live on, albeit in smaller numbers, in the winter warmth of your greenhouse. Deal to them now, while they are at manageable levels, rather that in spring when their populations explode. Check the under side of leaves for eggs and caterpillars, and squash any you find (gloves make the job easier). Hang sticky strips to catch white fly. Spray with a non-toxic solution of soapy water (¼ tsp hard bathroom soap to a litre of hot water, cooled before using on plants). If you haven’t planted out your greenhouse with winter veggies, remove any spent plants left over from summer, as they provide hiding places for bugs.

Wack the weeds
Winter frosts may be cutting your weeds down in the garden, but inside the warmth of your greenhouse, they’ll be happily growing. Pull them up as soon as you spot them. If they are perennials, cut them off at the base, pierce their stalk with a sharp instrument (such as a darning needle), place the stem of a funnel over the top, and pour boiling water and vinegar into the hole. If you have difficult-to-control weeds, such as oxalis, treat them with boiling water or an organic spray suitable for edibles (never use anything containing Glphosate, as even minute traces of it will put paid to tomato plants).

Soil – to disinfect or not
It’s an age-old question, and one that still has many greenhouse growers pondering. In general, if disease has not been present in the greenhouse, or present but manageable, it is always best not to treat the soil with any sanitising solutions. If you do, you risk destroying the soil microbiome in your greenhouse – the beneficial microbes that help carry nutrients to the roots of your plants. If you have been plagued with disease such as fungal mould, you may decide to seek a recommended greenhouse sanitising solution from the garden centre. But before you take this action, consider growing in pots of fresh soil, instead, or even digging out the existing soil and replacing it with fresh, weed-free compost. If sanitising the soil is your only option, keep your greenhouse well ventilated in future, so you don’t have to repeat the procedure on an annual basis.

Safe and sound
The major danger to greenhouses in winter is wild weather, which is why a strong, storm-proof Morrifield tunnel house is the way to go. It will take a heavy dump of snow without caving in, and its strong framework will hold its own against gales. However, no greenhouse is safe from flying objects. If you haven’t done so already, clean up your yard now by placing loose boards, empty planters, tools, paddling pools, and wheelbarrows into shelter. And tie down that trampoline!

Chit chat
Chitting is the art of pre-sprouting seeds or tubers before they go into the ground. In the case of potatoes, it gives them the chance to develop short, strong leaf sprouts that give the plants a head start in life, and encourage faster growth and a potentially heavier harvest. Your winter greenhouse is the perfect place to chit because chitting requires light. Place your selected potato seed in shallow boxes, one layer deep, and leave them in the greenhouse until sprouts are 1-1.5cm long. Select two or three of the best tubers and sow them into deep planters of quality vege-mix (or your own compost, if it is very loose). Leave the plants in the greenhouse until all danger of frost is past. In warm regions, the remaining chitted tubers can go into the ground, outdoors, covered from frost as required. Tip: to help you remember what variety of potatoes you are chitting, write on their skin with a non-toxic, felt tipped pen

Zones 3 & 4
Snow-go!
Snow can arrive at any stage in winter, and with climate change, it can hit where it never has before. Whether your greenhouse can support the weight of a snow fall depends on its structure and how old its covering is. But it also depends on the kind of snow that falls. A relatively thin layer of wet snow can be as heavy as a thick layer of light fluffy snow.
If you decide snow needs to be removed for the sake of your greenhouse, begin before the layer gets too deep. Use a soft kitchen (rather than a spiky yard) broom for the purpose (and wrap it in a towel if your think it has any sharp edges or protruding screws). Begin by gently removing snow from the north-facing roof of the greenhouse. This will allow sun to enter the structure as soon as possible to assist with the melt. Greenhouses are designed to support weight from above, not at the sides, so aim to remove snow from around sides of the structure . If you have gutters on your greenhouse, and you know heavy snow is predicted, it can pay to disconnect them in case they sag and break, and possibly tear the skin on your greenhouse as they collapse.

Bulb beauty
Bulbs are hardy treasures, but that doesn’t mean they won’t thank you for a little TLC. Hyacinth, especially, are prone to fungal attack, with mould eating away at their precious blooms while still in the bud. Bring your potted bulbs in from the cold, and let them luxuriate in the warmth of your greenhouse. As the flowers begin to open, transfer the pots onto a sunny window sill inside your home, and enjoy the colour and perfume.

Rest, relax, recover
Gardening is hard work, and winters can be long. Why not fix up a corner of your greenhouse where you can enjoy the heat on a sunny day, protected from cold winter winds. If you don’t have a solid surface in the greenhouse, rake a section of soil level, and place a mat of artificial grass over the top. Install your favourite deck chair and a little coffee table. Be sure to add some potted colour. If you have a small child in your life, and your greenhouse has a safe covering (polythene or plastic rather than glass), and does not contain toxic chemicals or chemical residues, you can even pop in a portable sandpit and a few toys so you can both enjoy your sheltered space together.

Sow me undercover now
Zones 1 and 2 Directly into the ground: beetroot, carrot, lettuce, garlic, microgreens, parsley, radish, spring onion. In seed trays or bags for transplanting or moving outdoors later: broccoli, cabbage, cauli, chives, Florence fennel, lettuce, rocket, silver beet, parcel, perpetual, potato, spinach beet, New Zealand spinach, winter spinach.

Zone 3 and 4 Directly into the ground: Broad beans, coriander, garlic, leafy Asian greens (such as Chinese broccoli ‘Gai Lan’, mibuna, mizuna, pak choi, and tat soi), cool season microgreens, spring onions, ‘Tasty Tendrils’ peas. In bags for transplanting or moving outdoors later: Jerusalem artichoke, potato, yakon.

Transplant me undercover now
Zone 1: Celeriac, leafy Asian greens, lettuce, hybrid spinach, zucchini.

Zones 2, 3 and 4: Broccoli, celery, cabbage, cauli, kale, lettuce, parsley, silver beet, parcel, perpetual, rocket, spinach beet, winter spinach.

New & Views

With Winter on our doorstep now is the time to check for any damages to the cover. We do have All Weather repair tape that will mend any small cover damages and repair or replace tired parts. We do have all replacement parts  no matter how old your Morrifield Tunnelhouse is! Check out our Replacement parts page for a list of common parts.

The wind can certainly be very nasty at this time of the year. The most damaging wind is the Nor Westerly so we do recommend shelter for your tunnelhouse , especially from this direction. If you do have a really bad spell of weather with gales, close all vents, windows and doors until the storm passes. If you have a Tunnelhouse with doors in both ends the wind direction can sometimes be problematic with the wind pushing the doors open. A handy tip is to use a heavy duty spring loaded peg or bulldog clip on the bottom door track of your Tunnelhouse. On the plus side of Winter you can garden away undercover in your Tunnelhouse and your plants will love it!

A little snippet from the 80’s.. We are still standing!

Written by Diana Noonan on behalf of Morrifield Greenhouses
*Please note these are guides only