September is considered the peak planting time for sub-tropical gardeners. The soil is warming up meaning seedlings will jump out of the ground. The lack of humidity means that pests diseases are low, but regular watering is critical.
Make sure you take advantage of September and enjoy your time in the garden.
• Grow any herbs now – except for basil (it’s too early) and coriander (it’s too late).
• Grevilleas will be flowering away. Cutting flowers for inside the house will promote new growth and better plant health.
• Pruning of edible fig trees can be carried out. Be very vigorous – one-third can be cut off. Figs are only produced on new wood of the new season’s growth. Give them a good feed of general fertiliser.
• It could be a few months before we get good soaking rains and the drying September winds will suck the moisture from bare soil, so mulch your gardens to keep in available water.
• Dig up and divide canna lilies. Water them in well with a seaweed solution.
• It’s a good month to start the fruit orchard – plant mango, pawpaw, avocado, custard apple, carambola and sapodilla.
• Spray your flowering mangoes with Mancozeb or a copper-based fungicide to prevent the disease anthracnose.
• Watch out for rampant lawn weeds – especially bindii, clover and flatweed (or cat’s ear).
• Check azaleas for red spider mite (also called two spotted mite) and control them with a pest oil.
• Bananas need management to produce good-sized bunches including regular removal of suckers. Each clump of bananas should be made up of a mature plant, a half-grown plant and one sucker only. Allowing all the suckers to grow will mean that bunches are either small or non-existent.
• Established passionfruit vines should be fertilised in early spring, use up to 1 kg of blood and bone with 100g of sulphate of potash added, spread onto moist soil and mulch well
• Prune citrus lightly in spring. Pruning is only necessary to remove deadwood and keep the centre of the tree open and branches from crossing. Always remove shoots or suckers from below the graft as soon as possible, as they steal vigour from the tree.
• Custard Apple should be losing their leaves this month … so it’s time to prune them.
Vegetables
Plant carrot, choko, zucchini, sweet potato, cucumber, eggplant, beans, lettuce, radish, spring onion, squash, tomato, beetroot, capsicum, kohlrabi, okra, pumpkin, rockmelon, rosella, silverbeet, sweet corn and watermelon.
Flowers
Plant alyssum, bedding begonia, cosmos, marigold, boronia, salvia, petunia, aster, amaranthus, celosia, phlox, portulaca, sunflower, torenia, zinnia, ageratum, gloxinia, impatiens, calendula, Californian poppy, carnation, chrysanthemum, coleus, dahlia, everlasting daisy, gaillardia, verbena, gazania, gerbera, kangaroo paw, nasturtium, rudbeckia and snapdragon.