About Keran Barrett

Editor, The Gardening Magazine | www.keranbarrett.com.au |

Garden tasks for January

01 What do DO JAN 500.1

What to do this month:

This information is intended as a general guide only. Local conditions can vary and seasonal variations need to be taken into account. If in doubt, ask a horticulturist at your local nursery or garden centre. Go here for more information on climate zones.



  • Mulch garden beds with a 10cm layer of organic matter such as home-made compost, leaf mulch or well-rotted animal manures to prevent soil drying out from the summer heat.
  • Encourage plant roots to travel downwards in search of moisture, by watering deeply rather than applying frequent shallow waterings.
  • Spray prunus trees using pyrethrum to prevent pear and cherry slug or throw wood ashes onto the leaves to eradicate these irritating pests.
  • Check for citrus scale and if present, spray with white oil.
  • Keep an eye on houseplants that may need to be repotted or that crave extra water during hot spells.


  • Rejuvenate tired and pot bound indoor plants by soaking them in water for several hours before repotting using a quality potting mix.
  • Mulch shallow-rooted shrubs like azaleas and rhododendrons, and water deeply twice a week.
  • Check for infestations of red-spider mite and azalea lace bug during dry conditions. If you want to spray, use regular applications of pyrethrum but avoid using chemicals as much as possible, as pests can build up immunity to them. If you’re going to use a chemical, make sure you use one that is not going to upset predatory insects.
  • Mow the lawn on a high setting to prevent it from being scorched by the sun.



  • DahliasFertilise vegetables and annuals with a liquid organic plant food every few weeks to promote steady growth.
  • Always water the soil well before using a fertiliser to avoid burning the roots.
  • Pinch back some of the flower buds on dahlias and chrysanthemums to encourage greater flower production.
  • Lift and store until autumn all spring-flowering bulbs that have died back.
  • Install a drip irrigation system if you are going away on holiday. Connect it to an automatic timer so that all your plants, including potted ones, survive the season.


  • A squeeze of LemonIncrease air circulation to reduce fungal problems by removing weeds from around the base of plants. This is a difficult time for gardens because the weather is so hot and humid.
  • Remove faded flowers or fallen leaves, as these may be carriers of fungal spores.
  • Water plants at their base to avoid splashing water on foliage and flowers.
  • Feed roses using an organic slow-release fertiliser to encourage continuous flowering.
  • Feed citrus trees that may be showing signs of nutrient deficiencies. Take leaf samples to your local nursery for identification if you’re not sure what the problem may be.