The government is right to say Australia grows a surplus of food, but suddenly the cost of buying that fresh produce has leapt, a consequence of crippling drought followed by catastrophic bushfire and then, in places, flooding rain. As we garden in an increasingly surprising climate, the reality of organising a reliable flow of nourishing food to provide a household with regular, thrifty meals falls on those who have suddenly become unwaged. In some places, nurseries are being stripped of seedlings and packets of seed as a nation prepares to overwinter in self-isolation at home and in the garden. What climate zone is my garden in? What can I grow now? Why is crop rotation vital for success? Can I grow food in pots? So many questions to answer.
The quickest meal you will never need to grow is already in your garden. It’s waiting to be recognised by you. If you are one of those people who didn’t treat your garden to glyphosate, the world’s favourite herbicide, you can have your first feed from chemical-free, self-sown edible plants – ‘wild greens’.
For those who did use it, it’s time to lift your game and for me to put on my hat as Patron of the National Toxics Network Inc. Repeated use of glyphosate herbicide is now known to be a risk to human and environmental health.
Volunteer, or self-sown plants, can be a great addition to the garden, especially when things don’t go according to plan, click on the link below:
Volunteer Plants, Gardening Australia, Series 20 Episode 32
The next quickest meal you can grow is sprouted seeds. Up to the time a seedling produces its first pair of true leaves, it is more nutrient rich than at any other stage of its life.
No garden or balcony needed, you just need a well-lit windowsill and a few basic items. Sown in succession, you’ve got nutrient dense food in days.
I started sprouting mung beans when I was a child. Youngsters can play an active role in household nutrition as they practise sprouting seed and learning how to prepare meals with them, click on the link below:
Growing sprouts, Gardening Australia, Series 18 Episode 03
Food in containers
I have a garden, but I still rely on containers for some plants. You might have missed my demonstration at the Queensland Garden Expo on ‘Food from small spaces’ in the Giant Kitchen Garden.
If you have a balcony or a small courtyard garden, once you’ve gathered those wild greens and seed are sprouting on the windowsill, it’s time to turn your attention to growing things in containers.
A dwarf fruit tree can live its whole productive life in a container. A 60 – 80 litre container is sufficient for a dwarf mango, avocado or lemon. Do not waste money filling a pot like this with potting mix, instead make your own mix using equal parts of horticultural sand, garden soil and premium grade potting mix. Never forget to put crocks over the drainage holes – crocks must be curved so they hold back potting mix, preventing it from being rinsed out, but they allow water to drain through. Crocks are essential whenever potting mixes are used because they are full of partially composted bark. As bark decays it forms a sludge that can block drainage holes causing water to accumulate, potting mix to stagnate and roots to die.
Strawberry has shallow roots and it thrives in a container. In winter, I move them into a spot with full, all day sunshine. In summer, I move them where they are shaded from scorching hot western sunshine in the afternoon. I do the same with boxes of multiplier spring onions, a cultivar which reproduces by offsets (cloning), not seed.
I grow giant society garlic and tree onions in terracotta pots because unlike plastic, terracotta breathes. While onions like regular watering during the growing season, their roots are killed by stagnant, waterlogged soil.
I dislike styrofoam and I hate these styrofoam vegetable packing boxes being used once and then becoming instant landfill. However, you can easily convert them into serviceable self-watering containers, click on the link below:
Make your own self-watering pot, Gardening Australia, Series 24 Episode 34
I’m never without fresh, container grown herbs either. Some of the finest, most versatile herbs need damp soil, but this is hard to achieve when there are watering restrictions. But I have a simple, water-efficient system that guarantees me an all year round supply of zesty, fresh produce. Click on the link below:
Save water, even if some herbs like it damp, Gardening Australia, Series 30 Episode 23
Growing food in soil
For those of us fortunate enough to have soil for food production, I served my apprenticeship as a home gardener under the training of my four ‘Dig for Victory’ grandparents. For many years, I have given the talk ‘My Family and other Vegetables‘ to explain how my mob got through years of air raids and rationing during two world wars. Colchester, our home town, was the first place to be bombed by zeppelin. I’ve still got the postcard 🙂
I come from four generations of English farmers and gardeners. I was born in a house in London which my grandfather helped build (he was a quantity surveyor who also helped rebuild the Houses of Parliament after WW2) and I learned to garden in the ‘Victory Garden’ which my grandmother planted. My other two grandparents were lifelong allotment holders and they encouraged me to garden competitively.
My grandparents taught me that 100 square metres of good soil can feed an adult all year round. If this is possible in Britain’s miserable cold temperate climate, where it rains every third day, you get about 100 days of clear sky a year and occasionally the soil freezes solid for days, then you can replicate this success with flair anywhere in Australia.
To get an idea of how to set up a garden for the long term, you can click on the link below:
Having it all, Gardening Australia, Series 28 Episode 18
What to do in your garden now: a countrywide guide
There’s a distinct gear change as autumn establishes, and warm season crops and weeds are replaced by cool season ones. Changing conditions and changing crops are prompts for sustainable gardeners to improve the soil and to practice crop rotation. The simple act of, for example, replacing summer planted eggplant with cabbage seedlings after a little soil improvement brings multiple benefits.
A word on seed saving
First up, save seed from your best plants, your mother stock for next season. Routinely saving from your own crops is possible if you grow non-hybrid crops. These are variously called open-pollinated, traditional or heritage varieties in seed catalogues.
Your ‘best’ plants may exhibit different virtues: saving seed of your last lettuce to flower selects in favour of longer lasting plants, whereas saving seed from your healthiest tomato plants helps build resilience in your stock. You are in the driving seat, so you can select seed from your biggest plants or the fattest pods. In doing this, you are selecting in favour of plants that succeed best in your local soils and conditions – a process of localisation that can result in distinct advantages over packet seed imported and sold by commerce.
I recommend buying a copy of the Seed Savers’ Manual, published by Jude and Michel Fanton. Jude and Michel founded the Seed Saver’s Network back in 1986. I have been a director for fifteen or so years. There are over one hundred local seed saver groups which can be contacted via the website. The manual was revised in 2019, use it as your guide to saving the seed of over one hundred crops vital to home food security. It has many tips and tricks about keeping crops vigorous and true to type. You can buy a copy on line by clicking on the link below:
Buy a copy of the Seed Savers’ Manual or connect with your local Seed Saver group
Compost, the universal soil improver
Compost is the universal soil improver. By regularly digging in compost, the market garden at La Perouse, which happens to be Australia’s oldest Chinese market garden (in Sydney) has converted dune sand into soil that cuts like chocolate cake. In under three years, digging in compost converted the heavy clay subsoil in my Brisbane garden into something suitable for vegetable growing. Organic rich topsoil develops into a healthy rhizosphere, the zone in which an intricately interconnected, mutually-beneficial, living matrix seething with microbes, fungi, animals and roots, creates an environment for growing nourishing food.
If you can’t dig because the soil is full of fruit tree or palm roots, regularly mulching the surface with compost or any of a variety of leafy mulches, like shredded prunings, leaf litter, bamboo leaves or lawn clippings encourages earthworms to feed, dig, aerate, drain and cycle minerals through the topsoil for you. These little diggers facilitate the natural sequestration of atmospheric carbon dioxide gas; they help climate repair.
Rotate your crops each season
Crop rotation is vital as it frustrates pests and diseases, making life hard for them to flourish on their favourite hosts. Crop rotation has the reverse effect on food plants, it helps them thrive. In each rotation, grow new crops that are botanically unrelated to the ones you have just removed. So, by replacing capsicum (Solanaceae family) with kale (Brassicaceae family) you limit opportunities for pests, like root knot nematodes, to do their worst. This is the fundamental way that crop rotation operates, so understanding a little backyard botany can simplify food production and improve your harvest.
A word about climate
Plants are very responsive to global heating. Carbon pollution is altering the nutrient density of crops.
In the rush to share gardening information about what to sow or plant now, there’s a rash of social media posts sharing ‘Dig for Victory’ crop rotation plans. What worked in one climate zone eighty years ago will not be as effective now because nowhere on Earth has had a single month of ‘normal’ weather since 1985. That’s when Ronald Reagan, Margaret Thatcher and Bob Hawke were running their respective countries.
In 1958 celebrated gardener Harry Oakman wrote ‘Gardening in Queensland’. In it he said that corn can be sown every month starting from August until February. But now, Australian summers are a month longer. Winters are shorter and they have warmer nights. Our climate is in steep transition.
Things have shifted considerably since Oakman’s time, and to demonstrate how we need to garden in response to climate change, in 2017 I sowed a successful crop of corn every month of the year, sharing reports on social media.
I love old gardening books. It’s important to remember horticultural history and how people once did things. Look at the British cropping plan for a food garden during World War 2 (above). It cannot be adopted by Melbourne gardeners because their climate is drier and far hotter – and it is in transition. But the concept behind the crop rotation plan, which shifts the kind of crops grown to frustrate pests and disease, remains valid.
A word about climate zones
The Köppen climate classification is one of the most widely used climate classification systems. It’s complicated, so it is usually simplified in Australia to the broad categories given below. Look on the back of a seed packet and compare it with the original Koppen classification to see what I mean. This simplification upsets some experienced gardeners who are well aware that local microclimate can influence success. Learn your garden’s microclimates as you plan and plant. Keep a gardening diary.
Warm temperate zone
Crop rotation suggestion: anything in the tomato family, like eggplant, chilli and capsicum, can be followed by the onion family.
Right now, spring onions are one of the quickest and simplest to crop, and sowing or planting one row every fortnight will provide a succession. I never dig up spring onions, I just remove their leaves. I planted a bed of spring onions seven years ago and by trimming off a few the leaves at a time, they’re growing strong and they are self-seeding each spring.
Leeks also quickly establish. If you can find perennial multiplier leeks, once established they will provide a steady supply of leaves for nine to ten months of the year. Over the course of the year, maturing multiplier leeks produce offsets – cloned baby leeks – and these can be removed and planted like conventional leek seedlings when the adult leeks are harvested as food. Leek seedlings and multiplier leek offsets are best planted in a furrow made in well dug soil and then watered in. With practise, you can use the watering in process to settle soil around the leek roots. As they settle and straighten up, gradually backfill the furrow with topsoil over a week or two.
Buying onions sets (baby onions ready for fattening up) guarantees they will be virus-free and it also considerably shortens the time it takes to grow a crop from the beginning using seed.
Dig in compost, then rake in one handful of dolomite or lime to sweeten the soil. Dolomite contains both calcium and magnesium, both readily leached through soil by flooding rain and irrigation. I prefer using this to lime which only contains calcium. Both create the slightly alkaline conditions onions relish.
Cool temperate zone
Crop rotation suggestion: anything in the beetroot family, like silverbeet and spinach, can be followed by the cabbage family.
Even the most cold tolerant members, like savoy cabbage and Brussels sprout, flourish when planted into warm, compost rich soil. For best results, sow cabbages in early autumn or plant seedlings in mid-autumn. Right now radish and daikon, its larger relative, offer the simplest and quickest return. Sow in succession as with spring onion.
Weekly thinning of seedlings prevents overcrowding, essential if members of this family are to develop into robust, self-supporting plants. Use these thinnings as your first harvest.
Feed cabbage, kale and other brassicas once monthly with blood and bone during autumn, applying one handful per square metre. Then foliar feed fortnightly with seaweed solution or a flower and fruit fertiliser as winter sets in.
Semi-arid inland zone
Crop rotation suggestion: pumpkin and zucchini, members of the cucumber family, can be followed by the carrot family, including crops like Florence fennel, celery or parsley.
These crops are happy to grow in a bed previously enriched with manures and fertiliser, but if the soil needs more, just add compost. The carrot family doesn’t require highly fertile conditions, and too much nitrogen is a common cause of carrots with forked, twisted roots.
Root crops like parsnip and celeriac thrive best where soil is finely dug. Digging is most easily and successfully completed when soil is moist following a good shower of rain. In dry weather, water well the night before.
Cow, sheep, goat or camel manure may be added to replenish the organic content in preparation for growing these crops. These manures are excellent soil conditioners, they are not really fertilisers. Like compost they are low in nitrogen.
For good crops, grow the carrot family in a sheltered position, in evenly moist soil. Foliar feed fortnightly with seaweed or a flower and fruit fertiliser. Avoid seaweed that has been ‘beefed up’ by added chemical nitrogen, this kind of feed is too powerful.
Crop rotation suggestion: sweetcorn, millet and sorghum, members of the grass family, can be followed by tomato or potato. The ideal maximum daytime temperature for potato is between 15.5C – 19C, which is why potato succeeds better inland where the nights are cooler and less humid than near the coast. The last time my garden near Moreton Bay had a daytime maximum of 13C was 2011. My soil is 16.2C 1 metre down, which makes potatoes grow very fast. Winter temperatures of 25C and above stop the development of tubers.
Just like following cucumbers with carrots, if corn has been successfully cropped in a bed, the soil will still contain sufficient organic matter and nutrients to see a good yield from tomato and potato.
Buying certified disease-free seed potatoes guarantees you won’t introduce diseases into your garden. Place them somewhere dry and well-lit, like a windowsill, and wait for them to start sprouting before planting. Avoid full, all day sunshine which may shrivel or burn them. Sprouting takes two to three weeks.
Potatoes and tomatoes must have well drained soil. Plant tomatoes in 45cm diameter pots or in ridges of soil 15cm high. Train tomatoes, keeping foliage off the ground. Never wet the foliage of potatoes and tomatoes, this encourages foliar fungal disease. As soon as either crop begins flowering, they become more susceptible to disease, like potato blight or mildew. Remove all dead foliage and be prepared to spray with copper hydroxide to control them. Pick off any leaf-eating ladybirds and their larvae.
Crop rotation suggestion: replace members of the bean family (Fabaceae), like cow pea, mung bean, soya and snake bean, with corn.
Roots of the bean family accommodate bacteria-filled nodules (small swellings) where atmospheric nitrogen is converted into nitrates. Digging in their roots liberates this nitrogen as they decay, and this helps to nourish corn.
Corn is a hungry crop, succeeding in warm, evenly moist soil. Following leaching summer rain, it’s wise to dig in plenty of compost, and to rake in one handful of poultry manure per square metre.
Sow or plant seedlings. Grow corn in rows, using several rows of even length to create square blocks. Blocks assist wind-pollination and the production of cobs evenly filled with kernels. Hybrid corn can have a variable germination rate. Rats, mice, birds, slugs, snails and caterpillars can also mow through a neatly sown bed. My solution is to sow 10% more than I need and to sow corn individually in mini-tubes. Keep your back up stock after planting to fill any gaps as they arise.
When plants reach a metre high, mulch with a 3cm deep layer of lawn clippings or sugarcane. Foliar feed fortnightly with seaweed, blood and bone, or a flower and fruit fertiliser.
Crop rotation depends on changing crop families
* The onion family (Alliodeae) includes garlic chives, leek and onion.
* The carrot family (Apiaceae) includes carrot, celery, celeriac, Chinese celery, coriander, fennel, Florence fennel and parsley.
* The daisy family (Asteraceae) includes chicory, endive, Jerusalem artichoke, lettuce and radicchio.
* The cabbage family (Brassicaceae) includes broccoli, cabbage, cauliflower, kale, kohl rabi, mustard and radish.
* The saltbush or beetroot family (Amaranthaceae) includes beetroot, English spinach, Good King Henry, huauzontle, mangelwurzel and silverbeet.
* The tomato or potato family (Solanaceae) includes eggplant, chilli, capsicum and naranjilla.
The bean family (Fabaceae) includes broad bean, pigeon pea, snow pea, garden pea, sword bean.
Root knot nematodes aren’t always mentioned in crop rotation plans, often because they were written for climates cooler than Australia.
Nematodes are one of toughest pests to control, and attack most of our favourite crops. Nematodes thrive in warmth, in evenly moist soils, especially those starved of organic matter. Weeds can be nematode vectors.
Attack symptoms include yellowing foliage, generally stunted growth, reduced yields, and premature death. Bad infestations may kills seedlings. Tumour-like growths (galls) on roots provide easily recognised evidence of attack. Large, ugly galls are sometimes confused with small, beneficial nitrogen-fixing nodules found on healthy plants in the bean (Fabaceae) and sheoak (Casuarinaceae) families.
Manage nematodes by:
* Eliminating sources of cross-contamination. Completely clear raised bed or garden beds of crops at the end of each rotation;
* Avoiding growing crops alongside nematode hosts, like grape, Jerusalem artichoke, peach, pineapple and sweetpotato;
* Killing nematodes in crop residues using hot composting;
* Growing a crop of mustard or French or African marigold, or Stinking Roger (Tagetes minuta). Dig this in, keeping the soil moist while it rots, and fumigate the soil;
* Sowing a green manure of barley in the cool seasons, or sowing corn or Chinese spinach (Amaranthus spp.) in the warm seasons. Dig this in when it’s 30cm high. Pest nematodes don’t feed on these plants and starve;
* Encouraging predatory nematodes, their natural biocontrol, by routinely adding plenty of organic matter;
There’s also a quick fix. I demonstrated how to save a nematode infested crop of rosella long enough to get it to harvest using an organic soil drench. Click on the link below:
How to make a nematode busting soil drench. Gardening Australia, Series 27 Episode 10.
Jerry Coleby-Williams RHS, Dip. Hort. (Kew), NEBSM
Director, Seed Savers’ Network Inc.
Patron, National Toxics Network Inc.
Patron, Householder’s Options to Protect the Environment Inc.
30th March 2020
Jerry started giving gardening advice when he was managing a production nursery in cold temperate London back in 1982.
He has gardened in dry temperate Perth, warm temperate Sydney, and subtropical Brisbane. He has been giving gardening advice to the public since he managed Sydney Botanic Gardens from 1992, and started radio talkback gardening three years later.
For ten years, Jerry wrote gardening stories, diaries, calendars and advice in national gardening magazines, including Gardening Australia magazine. He was also the Horticultural Editor of the Organic Gardener magazine.
For a while, Jerry boosted Brisbane’s 4BC Radio talkback gardening audiences – they averaged 65-85 questions in a 1.5 hour commercial radio show, a high point in the radio’s thirty five years of operation, until the show was axed in a corporate takeover.
This website http://www.jerry-coleby-williams.net and Jerry Coleby-Williams’ Public Facebook page are followed in 109 countries.
Jerry answers 9,000 – 10,000 gardening questions free out of his spare time each year. He answers single gardening questions only. Keep them short and concise.
Once the Coronavirus Pandemic has passed, Jerry expects to continue opening Bellis, his affordable, sustainable house and garden to the public as he has been doing since 2007.
Jerry continues offering sustainable gardening solutions with ABC Radio New England North West gardening talkback. Call: 1300 648 222. You can listen online.
5 Comments Add yours
Great read. You mentioned horticultural sand to use when filling a raised bed. As there are many different sands in a landscape yard, non are called horticultural sand. There are the course river sand, fine sand, sand for brick laying with a sort of clay content. Which sand ru referring to as horticultural sands. Regards ralph
If you have no idea of this basic difference in particle size and chemistry, buy a small sample bag of horticultural sand from a hardware store chain, like Bunnings. Horticultural sand is totally different from beach sand and builder’s sand. If a seller can’t tell the difference, shop elsewhere.
Excellent and timely advice for all
Thank you Jerry – your advice is a treasure chest! Sharing widely. Cheers
Thank you. Happy gardening! 🙂