Your plants (and probably you!) might be exhausted after a long, hot and hopefully productive summer. Some can be coddled along a bit more, others may need to be terminated; the plants, not the gardener!
Heavy feeding crops, such as tomatoes, cucumbers, capsicum, courgette and eggplants will have exhausted most of the nutrients supplied at planting. Now is the time to be feeding heavily with fast-acting fertilisers and liquid manures. The growing season can be extended by using frost cloth or cloches to reduce wind chill, trap some of the sun’s rays and reduce heat loss overnight.
Plant fast growing greens like lettuce and spinach to take up the slack until winter crops such as broccoli, cabbage and cauliflower start coming on. Onions, garlic, carrots and leeks can all be planted now. Celery, parsley and coriander are also good crops for this time of year, tending to bolt to seed less than in the summer months.
Keep an eye out for summer crops that have gone to seed; just leave the seed heads (or pods) on to fatten up. Harvest them once they have yellowed off and then finish the drying process by laying them out on mesh in a dry area before popping into dated and labelled paper envelopes. Good seed can last for two seasons if they are stored well, which means you always have some spare in case of a crop disaster. Many crops such as strawberries, blackberries, raspberries and boysenberries produce runners now, which are easy to pot up for planting out later into a new bed.
Strawberry runners are easy to pot.
Leeks are an easy autumn crop.
Alas, the bounty of summer is almost over.
The cooler, drier months of autumn are perfect for rejuvenating your soil. The warm, moist but not yet sodden soil is easier to work, and the weather is less exhausting for the gardener. I like to add a 2-3cm layer of compost to the beds, with a dusting of dolomite (or lime) and gypsum. As a rule of thumb, the dusting should look about the same as a well-floured ciabatta bread.
This combination is like gold for earthworms and microorganisms. Lime and gypsum need time to dissolve and move through the soil so autumn application is a good idea. Other fertilisers dissolve more readily in heavy winter rain and tend to leach out of the soil more easily, so applying these just before planting is a better option.
Most crops hate wet feet and many soil-borne diseases thrive in wet conditions. If your beds are not already raised, now is a good time to do this. Raising the soil level by even a few centimetres can improve drainage, which also keeps the soil slightly warmer. A raised bed can be as simple as digging out paths and using this soil to mound up the beds.
To reduce disease risk over winter and cut down on pests and diseases next summer, completely remove any weeds and old vegetation from beds and paths. Disease spores and pests will hibernate on these. Bare soil is an invitation to weeds; you can reduce weeds by mulching the soil or take advantage of the downtime to grow a green crop such as mustard, oats, lupin, peas, phacelia or buckwheat. Green crops reduce soil erosion and compaction from heavy winter rain, reduce pests and diseases in the soil, and add to soil nitrogen, carbon and humus levels.
Give any surrounding trees and shrubs a good haircut. The winter sun sits lower in the sky so nearby trees shade more. I always like to start my winter pruning season in autumn; sounds strange I know, but I can’t wait to get started and then I don’t have the big rush just before spring when there are so many other jobs to do in the garden.
My plums have already been pruned – straight after harvest is the best time to do these.
Table grapes are next as, like plums, they are so vigorous that pruning before leaf fall hardly makes any difference. Apples, pears, stonefruit and figs follow – usually by end the end of May when they have lost most of their leaves. I leave persimmon to the last of all the deciduous trees, as the autumn colours are just so gorgeous. Cherry guavas, macadamia and feijoas are pruned straight after fruiting for height and width control.
Autumn rains are a trigger for tree planting time; with warm moist soils and mild weather.
This is the best time to plant citrus, subtropicals and any other evergreen fruit trees, with deciduous trees best planted in winter. It’s also the best time to get slow-acting fertilisers such as lime, dolomite, gypsum magnesium sulphate, sulphate of potash (the granular, not crystalline form), superphosphate and animal manures around the drip zone of trees while the roots are still active.
Once all that lot is done, you can put your feet up in front of a toasty fire for the winter!