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September Garden Guide

Spring has sprung and you can enjoy all the hard work you put in during winter. But there’s no resting on your laurels for the busy gardener… Here’s what you need to focus on this September.


Let’s celebrate September by planting a tree (or lots of trees!) in your garden. To get you inspired, we’ve gathered together some useful hints and advice.

Before your plant:

  • Choose a tree that suits your needs: do you want evergreen foliage, shade or a tree that will attract birds to your garden?
  • Buy a tree that is free of any signs of pests or fungal diseases.
  • Avoid long, spindly trees. Rather choose a shorter tree with sturdy lower branches: it will be less likely to topple over once you plant it.
  • Handle your new tree carefully: don’t pick it up by the trunk and provide some barrier protection when transporting it so that it doesn’t get “wind burn”.

When you plant:

  • Dig a square (not round) hole measuring 60cm x 60cm. Square holes encourage the roots to grow sideways.
  • Add 2 handfuls of compost, half a cup of bone meal and half a cup of 2:3:2 fertiliser to the soil.
  • Mix the soil well and fill up the hole with water.
  • Plant the tree at the same depth as it was in its packaging.
  • Firmly press down the soil around the trunk and water well.

Plant and Sow:

  • Dahlias thrive in full sun and like soil that is rich in phosphate and potash. Add plenty of compost and well-rotted manure to your soil for best results. After planting, apply a layer of mulch at the base of the plants to reduce water evaporation from the soil. Pinch out small side shoots as the flowers grow to encourage the development of giant blooms. Stake dahlia stems as they grow to protect them from the south-easterly winds that lie ahead in summer.
  • Vegetables: climbing beans, beetroot, celery, corn, cucumber, brinjal, lettuce, melons, parsnip, peppers, potatoes, pumpkin, radish, tomato and watermelon.


  • Feed roses with 8:1:5 fertiliser to encourage a beautiful flush in October.
  • Feed lawns with 2.3.2 and 4:1:1 fertiliser
  • Feed shrubs and trees with 3:1:5 fertiliser

Extra care:

  • Treat iron deficiency (yellowing leaves) in your gardenias with iron chelate.
  • Cut back fuchsias to encourage bushy growth.
  • Mulch azealeas and camellias with well-rotted pine needles or bark chips once the flowers have faded. Feed with a high nitrogen fertiliser.
  • Enhance the blue of your hydrangeas by watering them once every two weeks with a weak aluminium sulphate solution (25g in 5 litres of water).
  • Spray roses with a rose cocktail made from one part Rosecare, one part Trelmix, one part Seagro, one tablespoon of vinegar and one teaspoon of dishwashing liquid. This will help to protect your roses against pests and fungal diseases.


Grow your own: Tomatoes

Tomatoes thrive in both garden beds and pots and are available in so many easy-to-grow varieties – why not grow a whole selection for fun colour and flavour in salads? Kids can also help in the garden by growing their own cherry tomatoes in pots.