The time to start new plants from seed is coming to an end, but there are still a number of things you can plant for fall, winter and early spring eating: arugula, corn salad, mescluns, mustards, pac choi, radish, and turnips. If you want more kale, chard, spinach or Chinese cabbage, look for healthy starts at local nurseries. Later in the fall you will be able to plant garlic.
Keep watering! Our long dry summer has left many plants parched, so keep plants well watered until the rains begin. Pay particular attention to camellias, rhododendrons and azaleas. A shortage of water at this time of year can cause flower buds to drop next spring before they open.
Unfortunately, the warm dry weather is perfect for powdery mildew. The white splotches that appear on members of the squash and some flowers, such as roses, lupines and phlox, are a form of fungus that appears when days are warm and nights are cool. While unsightly, perennials will survive it, and vegetables can be harvested. Keep plants growing vigorously with liquid fertilizer and spray with a solution of 1 tsp baking powder to 1 litre of water, with a few drops of liquid soap to act as a sticker. Or use a fungicide like Defender on ornamental plants. If leaves are green under the white blotches the leaves are still feeding the plant so don’t remove them, and yes, you can compost them when the plant is done.
Clean and tidy the greenhouse to get it ready for tender perennials to come inside at the end of the month.
Keep up with the deadheading. Not only will you remove a potential source of disease, but this simple act will encourage many plants to produce a new flush of flowers.
Lift maincrop potatoes if you haven’t already done so. Leave them out to dry before storing and store only undamaged ones in a dark frost-free place, in paper sacks tied at the neck. There is no hurry to reduce the temperature of potatoes immediately after harvest. Temperatures between 10-15 °C promote the development of a layer of protective corky tissue on the skin, and the healing of any minor wounds. After 2-3 weeks move them to a cooler spot, storing them in the dark, at temperatures between 5-10 ºC.
Top tomato plants to stop them from trying to set more fruit. It won’t develop in time and topping them forces the plants to concentrate on ripening fruit already there.
Keep on top of brassica pest control on over wintering cabbages, broccoli and Brussels sprouts. Whitefly and cabbage aphid can build up over the summer and survive the winter, ready to move on to new spring crops if the cycle is not broken. Pick off infested lower leaves. Spray with insecticidal soap if infestations are bad.
Plant fruit trees and shrubs. Fall planting allows roots to become established before winter, as the soil is still warm. Choose fruits and varieties that will suit the site you have in mind and look out for cultivars that show resistance to pests or diseases. Fruit trees and bushes are going to occupy the same piece of soil for many years, so good preparation of the site in advance of planting will lead to best results.
Towards the end of the month harvest autumn fruiting raspberries. After picking the fruit do not prune the canes immediately. Cut down to ground level in late winter or early spring. For summer fruiting raspberries, finish removing this years fruited canes, tie in new canes and remove any weak or damaged canes.
Prune blueberries any time between now and late winter. Aim to remove about one third of the bush each year. Cut back low down to encourage new shoots from the base of plants. Increase your stocks by taking cuttings from healthy bushes. Choose hard wood about pencil thickness and 20-25cm long. Leave all the buds in place and bury the cutting up to half its length in open ground.