Temperatures have plunged this winter and frost has been widespread across the Highveld. Gardening successfully in frost belts requires some careful thought when it comes to planting, and some innovative techniques when protecting plants.
There are several types of frost.
White frost
The most obvious and common kind of frost we get is white frost or hoarfrost. This occurs when the air cools to saturation point and dew forms on the ground. The air temperature then drops again and the dew freezes into tiny ice crystals. This kind of frost is harsh, but several of the hardy species of plants can withstand it.
Black frost
By far the most devastating frost for gardeners is the killer black frost. It occurs when the air is too dry for a white frost to form. It results in the sap inside the plant freezing and the colour black refers to the colour of the damaged plant tissue.
Frost protection
One of the best ways of protecting you plants is to wrap them in some form of protective covering. Most nurseries stock frost protection sheets, which are perfect for seedlings and vegetables.
Hessian, nylon sacks or straw are also commonly used.
Avoid using black plastic bags unless you are going to remove them during the day because your plants can be damaged by excessive heat.
Frost-sensitive plants
If you want to keep frost-sensitive plants alive, move them to sheltered spots beside buildings, walls, hedges and other large permanent structures. Consider planting them on the north- or west-facing sides of the property. If you want to a low- maintenance winter garden, plant species that can survive sub-zero temperatures. Hardy aloes, yellow Euryops daisies, lion’s ear (Leonotis leonurus), camellias, pansies and red hot pokers are among those that thrive in frost belts. - Saturday Star