Garden tasks for September 2105

Gladioli corm
Gladioli corm

Flower garden

  • Plant new perennials, but take care with tender plants – it’s best to wait till all danger of frost is over.
  • Continue planting dahlia tubers and gladioli corms for summer display.
  • Prolong blooming of early spring flowers, such as cineraria, pansies, poppies and primulas by liquid feeding and removing faded blooms. Check for caterpillars on your cinerarias and dust with derris dust if necessary.
  • Be vigilant with slugs and snails – protect young seedlings with Quash slug bait.
  • Feed your spring flowering bulbs with bulb food to ensure good blooms for next year.
  • Feed and mulch all roses, trees and shrubs.
  • This is still a good time to plant trees and shrubs, particularly camellias and rhododendrons.
  • Plant out violets and herbaceous plants.
  • Complete pruning of fuchsias.
  • Divide and replant primroses and polyanthus when flowering is finished.
  • Sow seeds and plant seedlings of ageratum, wallflower, Californian poppy, carnation, viscaria, begonia, celosia, gerbera, honesty, marigold, petunia, everlasting daisy, phlox, salvia, verbena, statice, sunflower, dianthus, aster, alyssum, nasturtium, gazania, geranium, impatiens, sweet-pea, coleus, cosmos, gypsophila and chrysanthemum.

Fruit and vegetable garden

  • Complete vegetable garden preparation, digging in plenty of compost.
  • Plant out early-crop potatoes after sprouting, and earth up any earlier crops.
  • Sow more peas, and earth up and stake those already up.
  • Dwarf beans can be sown at the end of this month.
  • Plant or sow new asparagus beds.
  • Sow lettuces, leeks, cabbages, tomato, capsicum, courgette, eggplant and cucumber ready for transplanting later.
  • Transplant your summer vegetable seedlings into the garden: lettuce, cabbage, leeks, and silver-beet.
  • Finish onion planting and keep your hoe going between crops.
  • Plant citrus and fruit trees, and feed existing trees with citrus fertiliser – water in well.
  • Spray stone fruit trees with copper to protect from leaf curl disease.


  • Sow new lawns and feed existing ones with lawn fertiliser – water in well.
  • Mow and roll lawns regularly.

Second thoughts

September is an ideal time to repot and feed houseplants, and to plant hanging baskets and terracotta pots for summer display.