Going into the garden and picking your own fruit and vegetables in prime condition is one of the great pleasures of life, as those who are able to do it will confirm. Fresh fruit and veg from the garden just seems to taste better – partly because it is harvested at the peak of maturity, flavour and nutrient value. In the future, though, growing our own fruit and veg may prove to be a challenge, given the reduced rainfall in recent times and the prospect that drought conditions may recur more frequently.
Water restrictions, which limit the operation of low flow watering systems to once a week for just three hours, add to the challenge.
However, many fruits and vegetables can produce quite well with limited watering, and it is possible to get worthwhile results from growing vegetables and fruit with some simple additional measures. like all plants, fruit and veg need water to grow. So when water supplies are limited, it’s a matter of getting the best results from the water available. Here are some basic guidelines:
- Grow the most high-value and water efficient crops – that is, those which produce the greatest amount of most desired fruit & veg for each litre of water.
- Grow crops that will produce with limited or no supplementary watering.
- Grow crops that produce during the cooler months. This takes advantage of autumn, winter and spring rains – doubly so, because evaporation rates are lower then too.
- Adopt water-efficient methods and practices to get the best use from every drop.
You don’t have to abandon summer, though. Reasonably water-efficient summer vegetables include tomatoes, capsicums, cucumbers, dwarf beans and zucchini. Cucurbits like cucumbers, marrows and zucchinis need pollen transferred from male to female flowers for best results. Grow one to three of your favourites to get a useful supply. Some vegetables will produce worthwhile results with limited water. Asparagus, once established, will produce a crop of spears in the spring before the summer heat Vegetable crops that will grow and produce during the cooler, wetter months include most of the root crops, the brassicas – especially the orientals like Bok Choi, Wong Bok and Pak Choi – early onions, potatoes, broad beans, peas, spinach (not silver beet), some salad greens like mustard and cress and many herbs, particularly the perennials like parsley and mint. Check a good planting guide for the best times to plant. The Yates Garden Guide has an excellent vegetable planting calendar. Many books and magazines on veg growing also contain a planting guide. Use the planting times specified for a mild or temperate climate.
Windy conditions will increase evaporation, cause a lot of damage to plants and reduce yields. If wind is a problem, construct a windbreak around the veggie patch from hessian or other suitable windbreak fabric.
Citrus, and the tropical and sub-tropical fruits, are the first to suffer when water supplies are limited. If you have old, unproductive trees in poor condition, this maybe a good time to let them die. Keep young citrus compact with tip pruning, and thin out excess fruit.
Most deciduous fruit trees can survive quite well and still produce good crops with less water. Keep trees compact, under three metres high and wide by removing excess growth monthly during spring and early summer. Also, thin excess fruit when it is pea-sized so that remaining fruits are no less than 10cm apart.
Keep under the trees mulched and free of weeds. Confine watering to three critical periods. These are: after flowering (only if spring is dry); late spring/early summer for next season’s buds; and the last few weeks before harvest for good fruit size. Pomefruits, particularly pears and quinces, will withstand dry periods better than stonefruits. Loquats flower in the autumn and fruit in the spring so they don’t have to carry a crop during summer. Fig and mulberry trees can crop with little supplementary watering. Persimmons are good value because they flower, set fruit and produce most of their seasonal growth before Christmas. Pomegranates also will grow and produce quality fruit with minimal extra watering.
One of the best assets in the garden, of course, is a grapevine over a pergola. It will grow with minimal extra water, provides welcome shade and cool, succulent fruits for hot summer days, and then lets the light in during winter.
For something different, try capers (Capparis spinosa) – tough and very ornamental and you get capers after a few years.
You might even want to revisit Australian bush tucker plants. Here are some that you might be able to find and are worth growing both as ornamental and productive plants (but then aren’t they all ornamental?). Trevor Christensen from the Gardens presented a useful overview at a botanic gardens congress a decade ago:
- Werrigel greens (Tetragunia tetnagonioides) – quick and easy to grow, nutritious, ideally cooked but apparently also eaten raw.
- Quandong (Sanmhee scutailustm) – beautiful fruits well known in Haigh’s chocolates, Beerenberg jams and delicious pies.
- Bush orange (Capparis mitchellii) – eaten raw or in desserts and cordials, slow-growing.
- Muntries (Kam pomifera) – often grown as an ornamental with the added attraction of edible fruit. Large-fruited cultivars are available.
- Native herbs and spices such as native mints (Mentha spp.), Sea parsley or celery (Apium prostratum).
- Lemon Myrtle (Bacidiousia citriodora) – although a rainforest species, its fairly hardy. Best pot grown. Used for flavouring condiments and a nice tea.
NOTE: This article was co-authored by Bruce Morphett, Technical Officer at Adelaide Botanic Garden.
Originally published in The Adelaide Review on 7 December 2007.