With very cold weather set to continue over much of Australia for some time, gardeners can protect young seedlings with an easy-to-make cloche. This simple structure named for the French word for ‘bell’ keeps plants warm on chilly nights and can be easily ventilated so that they don’t get too warm during the day. When the nights are milder, the structure can be easily folded and stored until it is needed again.
Instructions for making cloches can be found here: Cloche for seedlings.
** And remember to leave frost-damaged parts on shrubs until all risk of frost has passed. They may look unattractive but the burnt portions are protecting the plants from further damage.
Recently I visited Westport Public School at Port Macquarie to see their school garden. The garden is cultivated according to the lessons in the ‘Organic School Gardens’ program that I wrote for BFA and is available free to all Australian schools on the internet.
I was delighted to see how much the children and the dedicated staff at Westport have achieved in a few short months during what has been a very busy year. The Holiday Coast Credit Union and the local Bunnings store have shown great generosity of spirit in providing funding, equipment and labour to get the garden started. The children have had fun discovering how good organically-grown vegetables and strawberries taste and how vigorous and pest-resistant plants are when using organic cultivation methods, and are justifiably proud of their efforts. Well done, to everyone involved.
You can find the program at organic school gardens
I will take this opportunity to wish all my readers and their families a very happy and safe Christmas season, and may the spirit of Christmas and good gardening weather stay with you throughout the coming year.
With much of southern Australia experiencing extreme weather conditions, providing some shade for the vege patch and sensitive parts of the garden can help save water while reducing plant stress. See: Sun and heat protection
Mary recently posted a comment on that post giving details of a fully enclosed shade house that encompasses the entire vegetable patch. These structures can be effective where there is enough heat to dry leaves quickly, but there are a couple of points to be considered before making the decision to construct that type of shade protection for your garden.
Because these structures are fully enclosed by shadecloth, which prevents insect access, you will need to hand pollinate plants that require insect activity to produce crops. These include: the squash family (cucumber, pumpkin, rock melon, summer and winter squash, watermelon and zucchini), okra, coffee, passionfruit, strawberry and other berries, and cowpea. You may also have to hand pollinate broad beans if cropping is low. Sweet corn, popcorn and some varieties of tomatoes rely on wind movement for pollination. A fully enclosed structure will reduce air flow and these plants will also require hand pollination. Fungal diseases can be more common where there is not enough heat or air flow for leaves to dry quickly.
If you want to save seed from plants grown in a fully enclosed shade house, you will also have to hand pollinate: onion, celery, beetroot, silver beet, broccoli, Brussels sprouts, cabbage, cauliflower, kale, radish, swede, turnip, carrot, coriander, dill, fennel, and sunflower.
For those interested in constructing a fully enclosed shade house, I’ve included a link to Mary’s site in the ‘Blogs and other Sites’ panel on the right side of this page.
Some parts of Australia have been enduring extremely hot weather recently and, apparently, there is more to come. Last summer, a period of intense heat caused scorching in many gardens.
To protect our vege patch this summer, we have been busy over the past few weeks putting up arches to support shadecloth canopies over our vegetable beds. Although European-based garden texts recommend full sun for most vegetables, where summers are hot and air pollution is low, full sun can result in sunscald. While Australian natives have evolved to restrict loss of water through leaves in hot, dry conditions, very hot plants, especially those that originated in cooler Northern Hemisphere regions – such as most of our vegetables and fruits, lose a lot of water through their leaves in an effort to keep cool.
Providing some light shade during the hottest part of the day can prevent sunscald and, by keeping the plants cooler, reduces their water consumption, an important consideration where water restrictions apply. Each canopy is positioned to allow morning sun to reach plants, yet not restrict air flow around them. Poor air flow (such as in fully enclosed areas) can produce conditions suitable for some fungal diseases to establish. Light shade can be provided by shade cloth or old netting curtains or sheets.
We use a lightweight, knitted green shadecloth, which probably gives about 30% shade, and has eyelets along the selvedge edges to make it easier to tie to the posts with strong garden twine. This allows us to adjust the canopy as the sun moves to its highest position around December 22nd (Summer Solstice), then moves northwards in the sky through January and February, our hottest months.
We have used ordinary wooden garden stakes to support the canopies. Due to the extremely strong winds this spring, we have had to drive the stakes deeper into the soil for stability – a process easier said than done at our place. We have shale subsoil, and the stakes tended to veer off at strange angles when hitting a lump of shale. No doubt star stakes would be easier to drive home vertically, but we have a roll of 38 mm plastic irrigation pipe that is the right diameter to slip over the ends of wooden garden stakes. Star stakes require a heavy-duty 51 mm polypipe for arches, or the 38 mm polypipe has to be lashed to the star stakes instead of slipping it over the ends.
Once the stakes are positioned, in pairs, 1.5-2 metres apart along beds, the pipe can be cut to size. The formula is half the width of the bed multiplied by ‘pi’, plus twice the length of the pipe to extend onto the stakes. But, cutting each piece of pipe one and a half times the width of the bed plus 70 cm, is a good rough guide for most garden beds.
I then measure the length the arches cover and cut the shadecloth to that length plus a quarter of a metre. I then turn in 11 cm of shadecloth each end and, using a doubled strand of strong fishing line and a bagging needles (although gardening twine is shown here for clarity*), I run a line of stitching across the shadecloth, 8.5 cm from the folded edge. Then we slip the end arches through this ‘hem’ to anchor the shadecloth. *The polypropylene tends to abrade garden twine during periods of very windy weather.
If neatness is very important to you, you can brace the end arches to eliminate any sagging in the shadecloth but, without the braces, it does the job and that’s the important thing. Although the shadecloth can be removed when no longer needed, the arches can be left in position permanently to support netting, when needed, or frost protection, if required.
There are other actions you can take to protect your garden in hot, dry conditions. See Heat wave first aid
As you can see from the last photo (taken as the shade cloth was being installed), the tomato plants have responded beautifully in just three weeks.
Tip: if using wooden garden stakes, pay the little extra and buy the pointed ones. They are easier to keep straight when driving them into soil.
Autumn is a good time in most Australian gardening zones for maintenance work in the garden. My kitchen herb garden needed a serious renovation after three of our chooks escaped from their run during summer and made a total mess of everything. As summer was extremely hot and dry this year, I decided not to replant until after the weather cooled and we had some decent rain. Replacement plants were kept in the shade house until weather conditions were less stressful. In the meantime, I added some compost, worm castings, poultry based fertiliser, and seaweed tea to the soil; dug out weeds and errant roots of the mint family that had strayed far beyond their allocated area; and checked the soil pH. As it was barely on the acid side of neutral, I did not need to add any dolomite.
Although we grow some culinary herbs commercially, it is a nuisance to have to wander down to the herb beds when I want a few sprigs of something for a recipe. Consequently, my husband set up the framework for a kitchen herb garden close to the house. The finished garden measures 7 metres by 4 1/4 metres.
As the ground slopes slightly, the outer border of the garden was made from bricks retrieved from a demolished wall, and second-hand pavers provide pathways for easy access to all the herbs. The bird bath in the centre provides water for birds, bees and wasps that provide pest control and pollination. The garden has a permanent border of French lavender that serves several purposes. Lavender essential oils deter garden pests and, during the cooler months, the flowers are sold to a local florist. The hedge also protects the more delicate herbs from hot winds. There is a break in the hedge on the low side of the garden to allow cold air to drain away. A solid hedge traps cold air and allows frost to form. The herb garden also provides a suitable setting for my sundial.
I like to renovate my herb garden every three or four years as the perennial herbs such as rosemary, sage, thymes and mints don’t make as much strong, tender growth as the plants age. We find we get better production from younger plants that we grow from cuttings of the old stock. When I replant annual and perennial herbs, I always change their position in the garden as these plants also require a proper crop rotation to prevent soil diseases, and my herb garden is never completely full of herbs as I leave spaces for the rotation of annual and biennial herbs each season.
The garden looks quite bare at the moment (but it is easier to see the layout). I have very recently planted chives, rosemary, lemon thyme, marjoram, oregano, spearmint, eau-de-cologne mint, sweet basil, parsley, rose geranium, French tarragon and several more common thyme plants. The lemon grass clumps and the horseradish roots survived the chook attack, as did the soapwort. (Soapwort is not a culinary herb, but I didn’t know where else to put it). Coriander and dill will be sown later this month as they both do better here during the cooler months. After planting, the garden was mulched with finely chopped organic sugar cane residue as this will break down more quickly than other mulches, and add more organic matter to keep soil healthy.
Nights are still cold in many areas of Australia and New Zealand, which can delay planting of seedlings that love warmth. Cold soils delay root growth and frosts can permanently damage delicate seedling foliage.
You can get an early start with seedlings by covering them with a cloche (French for bell). Originally, cloches were round covers to protect plants but the term has been extended to include tunnel-like structures.
A simple cloche can be made from a length of clear, or light-coloured, plastic supported by hoops made from fencing wire or thin polypipe used for drip irrigation.
Agricultural plastic used for igloos can be quite expensive but cheap plastic drop sheets, mattress wrappings, or any large sheets of plastic will do the trick because they will not be required to endure long periods of hot sun. The length of plastic required should be long enough to cover the seedling area and have enough overhang to allow each end to be anchored.
Fencing wire (4 mm) is fairly easy to find at home or at the local recycling centre in rural areas, but metropolitan gardeners will probably find it easier to use polypipe and some wooden dowelling. Support hoops should have a generous curve so that foliage of the seedlings closest to the edge of the bed do not come in contact with the plastic cover, as this will result in cold being transferred from the plastic to the plant.
For wire hoops, cut the wire 1.6 times the width of the bed, and push the ends of the wire into the soil. Polypipe can be cut 1.5 times the width of the bed. Support the hoops on 30 cm lengths of dowelling, pushed halfway into the soil. Cover the hoops with the plastic, anchoring the sides of the cloche by lying garden stakes or pieces of timber along the edges of the plastic. The ends can be pulled down, folded to enclose the structure, and anchored with a piece of wood. Thin plastic can be loosely tied in a knot, and anchored with a tent peg. Use something to anchor the ends that is easy to remove because, during daytime, the ends are folded back across the hoop to allow good air circulation around the seedlings. When nights become warmer and seedlings are well established, the cloche can be folded and stored in an unobtrusive corner until needed again.
A cold frame will get your seedlings off to a flying start in spring. Cold frames don’t have to be complicated structures or require carpentry expertise. We make ours from some old bricks and windows, and a small quantity of watered-down white or cream house paint. Materials for this type of cold frame can be found at the local tip or building recycling centre. If you don’t have any left over paint, a small sample pot from the hardware store will provide enough paint for this job. Dilute the paint until it provides a slightly opaque coating to the glass. Some hessian bags, an old blanket, or a large piece of shade cloth or weed mat can be used as a cover at night to prevent warmth escaping.
The size of the cold frame is determined by the size of the window. If we only have a small quantity of seedlings that require warmth, we build it to suit one window frame. Three layers of bricks provide ample room for most seedlings. The cold frame will have to be set up in a warm spot to be effective. Close to a north-facing wall is best. The bricks in the cold frame will absorb and store heat during the day and release it slowly at night, keeping the seeds and seedlings warm. However, the cold frame can lose warmth through the glass at night, if it is not covered. Place hessian bags a folded blanket, or crumple shade cloth or weed mat on the glass panels in the late afternoon, and remove them mid morning when air is warmer.
Once seeds have germinated, prop the front of the lid open slightly with a half brick or something similar during the day to allow adequate ventilation.
This type of cold frame is easy to construct and to dismantle when the weather warms. The bricks and window panels can be stacked behind a shed or in an unobtrusive corner.
It’s a shame to throw empty plastic soft drink and soda water bottles into the recycling bin because they have a number of uses in the garden. If you cut the base from each bottle, you have an instant miniature green house. Cucumber, pumpkin, rockmelon, watermelon, zucchini and Brassica (cabbage family) seeds are particularly attractive to mice, and plastic bottles can be used to protect them in pots and garden beds. Once the seeds germinate, the bottle lid can be removed to provide ventilation for the growing seedling until it is strong enough to survive without protection. This will also protect them from birds that enjoy newly sprouted seeds. The green houses will also provide humidity for tip cuttings, and protect sensitive seedlings from cold.
Turned upside down, with the bottle neck buried in garden soil, plastic bottles can be used to apply water, through mulch, directly to the root area around shrubs and trees during water restrictions. Propped at a slight angle and filled with water, a couple of plastic bottles can be used to slowly release water to plants in large pots while you are on holiday, provided the plants are watered thoroughly before you leave.
I use a plastic bottle, cut in half, as a funnel for pouring liquid fertilisers into a watering can. If the fertiliser requires straining, I put a length of old panty hose into the bottle as demonstrated in the photo.
To protect our peas, beans, broad beans and corn from birds, we have to net the beds. We have started using supports made from lengths of polypipe slipped over the ends of metal star stakes, or strong wooden stakes. These arches can be left in position to provide support for netting or shade cloth, as required. Shadecloth will also provide some protection from frost.
Stakes 1.8 metres (6′) in length are suitable for beds that may contain climbing plants or corn. Star stakes measuring 2.25 metres (7′ 6″) can be used for small trees or larger covered areas. For star stakes you will need (2″) 51 mm *** diameter polypipe. Wooden stakes can be used when only (1 1/2″) 38 mm polypipe is available. A semicircular arch is reasonably strong, and this is the easiest to produce for smaller areas.
*** Please Note: Flexible polypipe is still sold in imperial measurements of (1 1/2″) and (2″). Polypipe sold as 50mm diameter is high pressure pipe. It is thicker and less flexible.
This structure over our pea and bean bed was made from 1.8 m. wooden stakes embedded in soil to 30 cm, which is as far as they would go in our soil. This resulted in 1.5 m. of the stakes left exposed. The stakes were positioned on each side of the bed, 1.5 m. apart, with approximately 1.5 m. – 1.8 m. between arches. We used the taller arches here to allow the remaining popcorn cobs to complete drying on the plants. This spacing provided arches with a height of approximately 2.2 m. The structure was erected very quickly and is easy to move if necessary.
To get an idea of the size of the arch canopy you will produce, measure the width of the bed, and divide the measurement by two. Add this measurement to the height of the stakes above the ground. For example, if you are using 1.8 m. stakes, buried 30 cm, you will have 150 cm of stake exposed. If your bed is 1.2 m. wide, half this measurement is 60 cm. Add the two together and you have 210 cm, or 2.1 m. – about 30 cm lower than the average ceiling. If you need a taller arch, use longer stakes.
To calculate the amount of polypipe you will need for each arch, multiply half the width of the bed by 3.1428 (or “pi” if you have a calculator with pi), then ADD 90 cm to allow at least 45 cm to slip over the top of each stake. For a bed 1.2 m. wide, 60 cm x 3.1428 = 188.5 cm plus 90 cm = 278.5 cm. Rounding it off, each length of polypipe would be cut to 280 cm or 2.8 m.
This is an example of a more permanent structure across a series of beds. It is approximately 6 metres wide. The arches are quite flattened and require support in the centre of the polypipe lengths. The gardener has used a strip of flat steel along the centre of the roof, welded to the tops of several galvanised iron pipes set in the ground.