Cold weather care for plants

It is July and the cold season is upon us.

As we are all taking cover from the cold weather, it should be noted that plants too need protection to ensure they survive the season.

Protecting the plant from adverse cold temperatures can be through various forms including mulching, covering with protective material or moving the (potted) plants to a shelter.

Stanley Ndung’u of Brooklyn Plant Centre situated along Ngong Road says the decision to cover the plant is based on its hardiness as well as location.

“While newer plants are more susceptible to the cold than well-established ones, a plant near a tree, fence or other structure is more protected,” he says.

The sentiments are evident at Hargwings Omondi’s backyard garden on his property in Nairobi’s Lavington estate.

While the lush hibiscus foliage that cover the backyard perimeter wall appear to be flourishing in the cold weather, the grass on his lawn tells of a different story.

“Since the cold weather set in, I have noticed change in grass including colour change and some withering,” he said.

His lawn enriched with the mondo and Arabica grass varieties sits at the centre of the seven by 15 metres yard and is surrounded on the sides by a variety of miniature trees including avocado, guava, mango, grape fruit and orange.

While protecting plants from the cold by covering may not be common locally, Mr Ndungu says it should not be construed that it cannot be done.

“Plants in a nursery can be covered using a cardboard box but you should be careful not to damage the foliage,” he said.

It may not be advisable to cover using cloths such as quilts because if they get wet, they will become heavy and this can mash down the plants. Commercial growers often opt for floating row covering – a thinly woven polyester cover- which reflects heat but allows irrigation to go through.

Aside from covering plants from cold-attacks, you can do mulching and this is ideal for protecting perennials and newly planted shrubs and trees.

“Mulch helps provide a layer of protection against the possibility of pushing the shallow roots out of the ground that may occur as the soil freezes and thaws,” Mr Ndungu explains.

Organic residues that can be used for mulching include hay, sawdust, leaves, shells, woodchips, shredded newspaper, wool and animal manure. Be sure to keep the mulch a few inches away from the plant to avoid rot.

Another method of protecting plants from the cold is through trunk wrapping and this is usually ideal for tree varieties that have thin bark.

Young, soft-barked trees and certain smaller species of trees are more prone to being eaten by foraging animals looking for food during the cold weather.

If your plants are in containers, you can consider moving them indoor or to shed to shield them from too cold temperatures.

The thing with potted plants is that their roots are much more exposed to weather elements unlike those that are in the ground.

A plant in the ground will have more cold hardiness than the same plant that is in a pot.

Yet another protective method is to put a wall/guard around the plants in order to shield them from cold winds.

The wind proof barrier can be made from rock outcroppings, stone walls, big clay pots, cinder blocks, or even a pile of bricks or tiles.

All these contain thermal mass, and when placed correctly in relation to your plants, can provide benefits to help your plants survive colder temperatures.

At the end of it all, it’s better to take precautionary measures to shield the plants from damage rather than doing nothing at all.