Winter in Australia can be anything from cool to downright cold, but July always comes with things to do in the productive garden
Cool & Temperate
Apply liquid fertiliser to stimulate growth on leafy winter crops, including cabbages and tasty greens such as rocket and soft-hearted lettuce. Apply the liquid fertiliser every 7–10 days.
Keep the greens coming by sowing seeds or planting seedlings every few weeks. Plant broad beans and spring onions; broad beans do best with a climbing trellis or stakes for support. Also plant silverbeet, English spinach and peas (podding and snow peas). There’s still time in July to plant perennial vegies such as asparagus and rhubarb. These long-lived vegies grow from crowns and do best planted into well-prepared beds with added organic matter dug in.
Keep inspecting all brassicas (kale, cabbages, cauliflower and broccoli) for snails, slugs and green caterpillars, which are damaging to many winter crops, especially new plantings. Handpick pests and check the backs of leaves for eggs and newly hatched caterpillars. Alternatively, spray caterpillars with Dipel (a Bt-based spray) and keep snails and slugs away with an iron-based bait, which is harmless to pets and wildlife.
While deciduous fruit trees and vines are bare, it’s a good time to prune for new growth, sort out broken or crossing branches and remove any diseased fruit or wood. Don’t put diseased material into compost heaps; rather, it can be buried or burned. Cut down the old stems of autumn-fruiting raspberries to ground level.
Right through winter, bare-rooted deciduous fruit trees are available. When buying a deciduous fruit tree, look for a good shape and avoid any with broken branches, poor branching or damage. Only buy trees that have well-protected root systems as dry roots can lead to plant death or trees that are slow to reshoot in spring. Check cross-pollination requirements. If possible, select a tree that’s already grafted with a pollinating variety. Where space is at a premium, look for dwarf fruit trees for planting in raised beds or large containers.
If trees have not yet begun to regrow leaves, apply a winter spray; use a copper-based one to protect from peach leaf curl and brown rot.
Compost & Soil
As July brings cooler temperatures, rates of composting slow down. To keep compost systems working through winter, regularly aerate the heap using a fork. Dig in a few handfuls of lime if the heap seems smelly. Balance large additions of autumn leaves with nitrogen-rich matter such as lawn clippings, manure and kitchen scraps.
Keep rodents at bay by keeping a lid on the compost. Prevent animals burrowing in by burying a barrier in the soil around the heap. Where conditions are wet, cover heaps to keep them from becoming wet and soggy.
Also keep worm farms in a warm, sheltered spot such as a verandah or carport as cold kills worms. Use worm wee to liquid-feed vegie crops. Weeds don’t seem to know it’s winter. Keep on top of winter weeds by lightly hoeing among rows of winter vegies.
The cooler weather is a good time to work on soil. If soil is poorly draining clay, dig in gypsum and organic matter to improve drainage and raise the soil level. Mulch worked areas and leave until late winter or spring for planting.
Water all crops, especially leafy crops and those growing in raised beds or containers, to encourage fast, tender growth. Liquid-feed the patch at least fortnightly. Harvest crops that are ready to use. Excess can be frozen. Keep up regular pest inspections. Keep an eye out for cabbage white butterfly caterpillars and grasshoppers — squash any you see. Dipel is a safe chemical treatment for the caterpillars you miss. Remove diseased leaves and cut off branches affected by scale.
Keep planting regularly so there are always new crops coming on. Sow beetroot, carrot, tomato and melon seeds. Also sow a block of sweet corn for one of the best homegrown flavours you can grow. Peas, particularly snowpeas, provide a fast, easy harvest in winter. Cherry tomatoes are also a stress-free winter crop in tropical and subtropical climates. Spring onions are also fast and rewarding to grow now.
Harvest citrus fruit as needed, keeping plants deeply watered, well mulched and weed-free. Spray trees with horticultural oil to reduce populations of citrus bugs. Only apply oil sprays at the recommended rates and don’t apply if the sun is warm. Combat other pests and diseases with a winter maintenance program of pruning, clearing and spraying. Also deeply water mango, avocado and custard apples. Lychees are ripening, so rebait traps to control early pest outbreaks. If winter winds are knocking flowers from fruit trees, erect a windbreak with shadecloth or hessian and start planning a living windbreak with local native plants.
Strawberries are flowering and fruiting now as days lengthen. Liquid-feed every 7–10 days for good flowering. Ensure there’s plenty of organic mulch to keep developing fruit out of contact with the soil.
Compost & Soil
Use this cool, dry part of the year to work on improving soil fertility and moisture-holding capacity. Dig compost and manure into areas that are being prepared for planting. Cover fallow spots with mulch or sow a green manure crop such as clover, which not only keeps the weeds away, but can be dug into the soil to improve its nutrients for spring growth. Mulches also prevent soils drying out. If an area is hard to dig due to clay, sprinkle over gypsum or water with claybreaker. Spread a layer of organic mulch such as sugar cane over hard soils to encourage earthworm activity, which helps make soils more workable.
Turn compost heaps and add extra moisture if the heap is dry. Material needs to be moist, not wet. Continue to add a balance of wet and dry materials such as vegetable scraps and lawn clippings layered with dry leaves and chopped disease-free garden prunings.
Written by Jennifer Stackhouse
Originally in Good Organic Gardening Volume 8 Issue 2