Frost Protection for Plants

Frost is a fact of life in New Zealand. While it might not seem like it when one hits, frost can actually benefit your garden. It helps control insect populations by disrupting the breeding cycles of many common garden pests. But that doesn’t mean it can’t cause damage, either.

How to protect plants from frost damage

Unfortunately, frost can cause widespread destruction to your plants and crops, so knowing how to protect them is important. There are several easy ways you can choose from to help protect your plants from frost.

Be on weather watch

Your first line of defence is to get to know the weather so you can deal with your plants accordingly, especially in winter when frost is more likely. Watch for cold temperatures and clear, windless nights; they usually mean a frost is on the way.

Cover your plants with cloth or other material

Covering frost-sensitive plants is a quick and easy way to protect them. A good rule of thumb is that it is better to be safe than sorry and cover when there is even the slightest suspicion of a frost. The covers go on early in the evening and are removed first thing in the morning.

You can use a range of materials, including frost cloth, newspaper, muslin, or even an old set of net curtains held together with clothes pegs. Just be sure to keep the cover off the foliage by using garden stakes to create a cage over the plant.

Frost cloth, available at most garden centres, is lightweight, affordable, and made from durable spun polypropylene. It’s designed to last for years, but make sure to dry it thoroughly before storing it away for the season to prevent mould growth.

Use a tunnel

Pre-made tunnels or cloches are perfect for protecting the vegetable garden. Tunnels are used as a mini greenhouse for the beginning of the season, but they can also double up as frost protection. You can purchase either polythene or fleece tunnels; both will work very well for helping your plants stay protected against frost.

How to identify and mitigate damage

If your garden gets frosted, damage to plants becomes obvious quickly. Shoots and leaves will often go black or brown and then turn mushy as frost destroys the cell structure of the plant.

Removing vs leaving the frosted plant

The question is: should these parts be pruned or left? Some gardeners believe that when a frost hits, leaving it on the plant can be beneficial. This will cause any new growth to be held at bay until all the severe frosts are over, preventing further damage.

Trade Tested recommends using a combination of both. For hardier shrubs that have been frosted, leaving the damaged parts of the plant and removing them later will be fine.

In the vegetable garden, be a little fussier and remove most of the damage, then replace the plant if necessary. Best practice is to always cover your plants to protect them from future frosts. Often, tender seedlings become just too damaged to grow properly; it is better to start again with new seedlings.

Choose Trade Tested for easy frost protection

At Trade Tested, we offer simple solutions for keeping your plants safe around the garden from cold temperatures during the winter. Make protecting your plants simple with our net tunnels and cloches, as well as expert advice from our friendly team. Order now.

Looking for more plant support? Browse weather protection and DIY pest control.

Contact us today with any questions or for more help shielding your plants.

What our customers think

“Well-made tunnel and easy to put together. They stop the birds, reduce wind strike, but let in light and water. Exactly what I needed.”

“Does a brilliant job keeping all the nasties out of our hard-worked crops. Had a storm the other night, and our grow tunnel is still standing. Very sturdy. Would highly recommend.”

“Absolutely ideal product. We were having a considerable problem with birds getting under the netting cover we were using. Not any more. They can't land on it and certainly can't get inside.”

Frequently asked questions

What is the best protection for plants from frost?

Frost cloth is a top choice as it’s lightweight, breathable, and reusable. For quick fixes, old sheets, towels, or net curtains work well when secured properly. Add mulch to insulate roots to help soil retain heat overnight.

Is frost cloth better than plastic?

Frost cloth is made from polypropylene plastic bound in a way that allows for more breathability and airflow than solid plastic covers. Its permeable structure helps prevent fungal growth, temperature spikes, and rot, reducing the risk of plant damage.

How do you put frost cloth on plants?

1. 1. Find breathable, UV-stabilised frost cloth made from polypropylene.
2. 2. Cover plants with the cloth in the early evening to trap daytime warmth.
3. 3. Use garden stakes or bamboo canes to drape it in a tent-like structure over the plants, preventing the cloth from touching them directly.
4. 4. Tightly secure the cloth with pegs or rocks.
5. 5. In the morning, take the frost cloth off once the sun is out.

What plants are susceptible to frost damage?

Tender vegetables and herbs such as tomatoes, basil, and capsicum, as well as tropical and subtropical plants like banana, avocado, and passionfruit, are susceptible to frost damage. Hydrangeas, citrus trees, marigolds and young seedlings are also some of the many plants that may face frost damage in particularly cold temperatures.