Autumn Gardening

autumn gardening

AUTUMN – a busy time of year for gardening enthusiasts!

The crisp morning air and longer nights is a sign that autumn has arrived in all its glory. To ensure a glorious winter and spring garden, there are many tasks to be performed in the garden. 

Trees and Shrubs

Contrary to belief, plants actually grow during winter, but adjust their objectives by using energy to establish roots instead of flowers, fruit or leaves. The soil temperature is still quite warm after the summer, therefore newly planted trees and shrubs can easily establish their roots.  Where the soil temperature does not drop below freezing point, the roots will continue to grow throughout the winter, despite the fact that they have few or no leaves at all.

By planting trees and shrubs now you can rest assured that the roots are well established by the time spring comes! Plants that are susceptible to frost, such as begonias and Fuschias, should be planted in spring.


A wide variety of bulbs are now available in your favourite nursery or retailer.  Bulbs require well-composted soil and lots of spare nutrition. Narcissus and daffodils carry only one or two flowers per bulb, so it is advisable to plant the bulbs in dense groups for a spectacular display of colour.  Plant ranunculus and anemone bulbs at two-week intervals to ensure a long flower display during winter.


There are a wide variety of seedlings available this time of year. Petunias bloom in a huge array of colours and flower for months on end. They will thrive in the hottest and driest parts of your garden. Pansies and violets are reliable and versatile and will do well in full sun to semi shade. Plant them en masse for a cheerful display of colour.

Primulas are easy to grow and can be planted in the shade.  They flower for extended periods and look spectacular in mass plantings.  Cinerarias also grow well in the shade.  Sweet Peas, Daisies, poppies, Lobelias and Namaqualand Daisies are all available now and can be easily established from seed. For long-lasting, vibrant colour, feed your flowering plants regularly with a fertiliser formulated for flowering plants.


Autumn is the ideal time to divide and replant perennials, thereby ensuring flowering in summer.


Start to cut the lawn shorter by setting the mower blades to the lowest setting.  This will encourage growth before the harsh winter season.  You still need to feed your lawn this time of the year for a lush, green autumn lawn.

Trees and Shrubs

Untidy trees and shrubs may get a last light pruning.  Don’t prune harshly as this will encourage new growth and the shoots will be damaged by the winter cold. It is extremely important not to prune winter-flowering shrubs.


Due to lower temperatures, there is a higher volume of water available in the soil available to plants as evaporation decreases due to cooler daytime temperatures. Furthermore, the shade in your garden will change at the turn of the season, so take into account that summer sunny areas may now become shady areas.  Adapt to the changing climate and gradually reduce watering.  Too much water can cause root rot, but remember that new plantings should always remain moist.


With new plantings, it’s important to stimulate root development by applying a high-phosphate or 2.3.2 fertiliser. Fertilise your entire garden, including your lawn, bulbs and seedlings, every four weeks with an organic fertiliser containing the three most important nutrient elements: Nitrogen (N), Phosphate (P) and Potassium (K).

Look for one that also contained many of the important micro-elements that plants require for healthy growth, such as Iron (Fe), Manganese (Mn), Copper (Cu), Zinc (Zn) and Barium (B) to name but a few. Zinc is especially important as it assists plants to resist the low temperature.

Diseases and Pests


Mildew, rust and powdery mildew are just a few of the fungal infections that are rife just before winter.  Treat preventatively, but if fungus is already prevalent, apply a systemic fungicide to prevent the fungi from spreading.


Ants are everywhere collecting food for the winter. To ensure that they do not hibernate in your lawn, you can get rid of them by applying an ant control agent. Certain products will destroy the nest, including the queen, within a few days.

Treat the rest of your garden with a systemic insecticide that should keep insects at bay until the start of winter.  Use a product that not only controls mole crickets, but also a variety of aphids and is extremely effective against the dreaded Italian cypress aphid.

Snails and slugs can cause havoc in your seedling and bulb garden beds.  Get rid of these munching molluscs by applying an organic snail bait in the late afternoon. In Autumn, also look out for wood-destroying termites. These termites cause massive damage to buildings and other wooden structures and are often undetected until the timber is severely damaged and exhibits surface changes.  You can prevent the destruction by preventative or corrective trench, nest and foundation treatment with preventative treatment.

Harvester termites harvest dead and living plant matter and can cause damage to grass, leaves, herbaceous twigs and seedlings.  They will invade and cause significant damage to lawns and gardens, to the extent of complete destruction.  Stop the destruction with a ready-to-use termite poison.

Remember there is a decrease in food availability for rodents.  Prevent them from coming into your home for food by controlling them with rat traps or responsibly used rodenticide.  Always use a bait station for safer control these disease causing rodents.

Do not let the approaching winter give you cold feet when it comes to gardening.  Use the last warm days to create a smoking hot winter garden. 

The Gardener