Garden Care in September

What to Do

September has arrived and spring is in the air! So much happens in the garden during this beautiful time of the year. It’s the season when gardeners plant with great conviction.


  • Prune away all dead, weak and crossing stems from roses.
  • Prune back spring flowering shrubs immediately after they have finished blooming.
  • Hopefully we have had the last of the late winter cold spell, so any frosted plant material can now be safely cut back.
  • Keep an eye on the topiaries as the quick spring growth can affect their shape.
  • As the lawn starts to look a little high, give it a mow with the blades set on high. Apply lawn fertiliser at the recommended rate. (Always check the instructions)
  • Water spring flowering shrubs like azaleas and deutzias to ensure a good show.
  • Deadhead your pansies and violas, so that they will continue to bloom through to November.
  • Stake alstroemerias and other perennials that have a tendency to fall over.
  • Allow Daffodils and Narcissus to die down naturally and go brown; thus forming next years flower bulb.
  • Repot any pot plants that look as if they could be ‘root bound’, ie the roots are growing out of the drainage holes. Either remove a little of the top soil and replace with new potting soil, or completely repot if necessary.
  • After doing this water the plant sparingly, so that the plants do not rot before they have started rooting. Never fill the pot plant up to the rim of the pot with soil, always leave space for watering.


What to Plant:

  • September is the ideal month to plant trees and shrubs in the garden. There is a large variety available from your local garden centre that will not only bloom in spring, but will attract birds and butterflies to your garden too.
  • The trees that will add beautiful colour to your garden are the paperbark acacia, fever tree, blossom tree and the forest elder.
  • Plant new curry leaf trees when all danger of frost is over. They are a member of the citrus family and need to be looked after in a similar manner.


  • Clivias commonly known as bush lilies bring spectacular colour to the shady areas of your garden during the month of September. They are not only indigenous but easy to care for and waterwise too. A great addition to any garden.
  • Popular shrubs to look out for are felicias, polygalas, carnations, argyranthemums and pelargoniums.
  • Plant climbers as the soil warms up so that new roots are encouraged to grow and establish.
  • Most herbs can be safely planted now. Dill, chervil, origanum, borage mustard, water cress, caraway, coriander, mints, penny royal, rosemary, fennel, basil, anise and summer savoury.
  • Plant seedlings of cabbage, lettuce, capsicum (peppers), tomatoes, peppers and egg plants.

What to Sow:

  • Sow early vegetable and salad crops in seed trays in a greenhouse or tunnel. When thinning out, use these for salads rather than discard.
  • Plant new lawn grass seed or grass plugs. It’s the best time for establishing a new lawn.
  • Sow seeds of cabbage, lettuce, tomatoes, peppers, eggplant, basil, anise, salad burnett, salad rocket and parsley.
  • Sow in situ: beans, swiss chard, pumpkin, gem squash, sweet corn, baby marrow, carrot, turnips, radish, beetroot.

What to Spray:

As all the “re-growth” for the new season starts, you will notice an increase in insects (not the "gardener's friend" type but rather the un-welcome ones) these will be feasting on the new tender shoots, so please be aware while walking around your garden.
Pest to watch out for are:

  • leaf gall on azaleas
  • thrips on gladioli
  • snails and slugs around newly planted seedlings
  • citrus psylla on lemons
  • check for weed growth in your lawn and apply selective herbicides where applicable.
  • if you planted impatiens in August, be sure to keep an eye out for impatiens fungus.

There will also be an increase in the number of weeds in your garden, so a great deal of the gardener’s time will be spent on these two chores!
No problem though, just pop into your local garden centre and pick up all the products you will need to protect your garden this spring!

What to Feed:

Time and energy must be spent on feeding the garden during September as plants push out their new growth; attention must also be given to your lawn as this will be re-paid with improved and lush growth during the year.

Feed strawberries, raspberries, logan-berries, granadillas and grapes with a general 3.1.5. fertiliser like 3.1.5 Rapid raiser, Vigarosa or Wonder Organic Vita-Boost.

Add organic slow reslease fertiliser to fruit trees and shrubs – remove the mulch, feed and replace the mulch.

Fertilise all fruit trees now with a general purpose fertiliser like 3.1.5 Rapid raiser, Vigarosa or Wonder Organic Vita-Boost at the recommended application rates.


Waterwise flowering plants are hardy and are exactly what the name says, waterwise!

These plants survive on minimal water and tolerate hot dry conditions. One of the easiest ways to save water is to go indigenous.

Plant gazanias, wild garlic, wild irises and of course the bright and beautiful vygies.

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