How to Protect Plants from Frost

May 15, 2024

As gardeners, we appreciate that our gardens will be exposed to a variety of weather conditions, including frost. Being able to know what to do to protect plants from frost is therefore a key skill to learn. Firstly, you need to know which of your plants are vulnerable to frost and secondly, what the best way of protecting them from frost damage is.

5 Ways to Protect Plants from Frost in Your Garden

Subtropical, tropical, recently planted seedlings, trees and plants with young growth are susceptible to suffering from frost damage. Even if you’re only growing those plants best suited to your local conditions, depending on their growth cycle, they still may be frost tender. Therefore, it’s best to know how to protect plants from frost using these any of these five ways:

Cut large plastic soft drink bottle in half across, and then place over the top of seedlings as a small cloche.
Build cold frames for your plants, which are essentially boxed gardens with ‘windows’ that tilt up and can be propped open during the warmer parts of the day.
Raised beds are becoming the norm in many NZ gardens due to them making gardening easier to reach. A raised bed will also have warmer soil than at ground level because cold air sinks to lower areas in your garden. Knowing this, you could also make the decision to plant your more frost tender plants in higher areas of your garden, or nearby a building for additional frost protection.
Water your plants and keep the soil moist. This is because moist soil can absorb and keep heat better and reduces the risk of frost damage.
Use frost cloth placed over temporary cloches positioned to keep the cloth off from touching the tree.

Remember that if any of your plants become frost damaged, do not remove the damaged foliage as this can encourage new even more frost tender growth to develop. Instead, simply leave it in situ until the risk of frosts has passed.

One of the great things about our native trees such as our l arge Kowhai are that they are perfect for growing in local conditions. While eight of the native Kowhai species do lose their leaves in the cooler months, they rarely need any frost protection once they are no longer seedling sizes.