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How to protect plants from frost damage


July 28, 2022


Searles Gardening Team

The threat of frost as winter approaches can play havoc in the mind of gardeners. The first frost of the season can be a real litmus test to see what new plants will survive. Some plants can tolerate some light frosts but not frequent and subsequent frosts. Most gardeners have chosen what plants grow well in their climatic zone and weather conditions, but some plants can still be surprisingly sensitive.

Firstly, a quick description of how frost can damage plants. Frost forms when the moisture in the air dips below freezing point (0C). Frost damage on plants and lawns occur when water in the plant's cell freezes and expands causing the plant cell to burst appearing as browning or blackening on the leaves.

Here are a few methods to protecting plants from frost damage.

1. Cover plants the night before a frost is likely

The quickness way to protect valuable plants from frost is to cover the plants the night before with a breathable cloth, sheet or blanket. Some sturdy plants can tolerate heavier covering. For more delicate leaf plants, use a lighter cloth. If wind is likely to come with the frost, secure covering with string, rocks, bricks or wire. Ensure the covering is removed the next day once the frost has occured. It is important the plant receives their normal day light and air ventilation.

Protect young seedlings by covering them with an empty inverted pot or a cloche. Light mulching around the seedlings may also create a protective barrier against frost damage.

2. Move sensitive potted plants indoors or to a protected patio until the frost has passed.

An added benefit is you get to enjoy the plant inside.

3. Liquid feed with an organic Fish & Kelp solution.

Use a combined tonic and fertiliser, such as SeaMax Organic Fertiliser Liquid, to promote healthy and strong roots and stem health to defend against some frosts. Apply SeaMax Organic Fertiliser Liquid every couple of weeks to strengthen their defence.

4. Raised garden beds can help.

Cold air sits in lower areas of the garden. Plant frost sensitive plants in higher areas of the garden. Raised garden beds will help keep plants off the ground.

5. Plant frost resistant varieties.

Many modern hybrids are bred to be more frost resistant. Look out for these varieties at your local gardening outlet. Also remember, if a plant suffers from severe frost every year and doesn't recover, maybe plant something else more suitable in its place.

6. Remember: Some plants can bounce back quite well from frost damage once spring has arrived.

New spring growth will quickly cover the damaged areas. Ensure you prune affected leaves and branches only when the frost has passed for the season. A liquid feed with Searles Flourish range of soluble plant foods to promote faster healthy growth.

Hedge effected by frost damage

Leave frost effected leaves on the plant as a protective layer and only prune off once the threat of frosts have passed.