Let’s get gardening Tackle frost, buy a big tree, and meet ecologist and winter’s number one fan, Dave Pepler

Frost occurs in South Africa as early as May and can still wreak havoc in the interior as late as September. The Highveld, KwaZulu-Natal Midlands and Karoo are particularly susceptible, which gives many gardeners quite a headache. However, the cold is also responsible for the beautifully intense orange, red and yellow leaves we see in early winter, and can result in extrasweet and tasty winter vegetables.

FOUR WAYS TO FIGHT THE COLD

1 Choose hardy stalwarts Many plants are adapted to cold conditions. Those with smaller, more delicate leaves are generally more frost-resistant than, for example, tropical plants with large leaves. The same applies to types with leathery leaves, such as viburnums and camellias. Deciduous trees such as magnolias have no leaves that can be damaged.

Plant enough evergreen trees that offer shelter to smaller shrubs and plants.

Snapdragons, pansies, sweet peas and violets aren’t scared of the cold and are a good way to add a little colour to your winter or early-spring garden.

Feel free to plant hardy vegetable varieties such as broccoli, cauliflower, cabbage, carrots, onions, spinach and beetroot – but forget about aubergine, pumpkin, tomatoes and cucumber if your garden gets very cold.

2

Plant with a plan Many exotic plants are frost-resistant but some don’t do well in South Africa’s hot summers – chat to your neighbours and ask your local nursery about what works in your area.

Try to plant frost-sensitive plants against a north-facing wall so that the heat stored in it at night will warm the plants as it is released. Remember, cold air is heavy and collects in low-lying areas, so plant where there is a good flow of air. Also try to plant new plants by early autumn so that they have enough time to establish themselves before the serious cold sets in. If you’re in an area that gets black frost, it’s advisable rather to plant in late spring, when all chance of frost has passed.

3

Be water-wise Water your garden in the morning. Lightly spraying the ice off the leaves before the sun bakes on them will help them handle the temperature change and prevent the plant cells from bursting. This also gives the soil enough time to drain and trap the heat. Wet soil releases moisture into the air, which can raise the temperature and keep the plants warm. Try to plant frost-sensitive plants against a north-facing wall so that the heat stored in it at night will warm the plants as it is released.

4

Dress them in a jacket Even frost-resistant trees and shrubs are vulnerable during the first three years. Cover youngsters in the early afternoon, while there is still warmth in the soil, with a frost blanket. Alternatively, drape an old sheet over supporting poles. Make sure the cover reaches all the way to the ground so that warm air is trapped inside. Remove it the next day once the frost has thawed.

A decent mulch of autumn leaves, old newspapers or grass cuttings will protect the roots, but don’t spread it right up to the plant stems. Fruit trees usually have thin trunks that tear easily if they shrink (because of the cold) and expand (in the heat) too quickly – so rather wrap their trunks in strips of cloth.