If you are wondering how to protect plants from frost even in late spring, you are definitely not alone. Spring frosts are not uncommon in many climates in the northern hemisphere, but this year the weather seems especially cruel for younger plants that cannot cope with large temperature swings as well.
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Colorado-based horticultural expert Gardener Scott recently addressed this pressing issue on a YouTube livestream, stating that the problem isn’t just the cold weather itself, but the fact that the garden soil keeps heating up and cooling down again – a very bad one Combination for many plants.
At what temperature should I cover my plants against frost?
Gardener Scott also stated that he answered the question, “What temperature should I cover my plants against frost?” in late frosts depends a lot on whether you get snow.
If you get a decent amount of snow along with a cold snap, it can “actually be a great insulator,” he explains. “Snow is pretty much constant at 32 ° F / ° C. So when your plants are covered in snow, they are exposed to that temperature.”
In particular, you shouldn’t worry about snow-covered plants in the cold season, such as cabbage – they are absolutely safe, “they even like it when it is snowing,” he says.
However, if you get frost without snow, you need to take additional measures to protect your plants from “severe damage” to their cells.
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How can I protect my plants from frost damage?
Particularly in light snow you should pay attention to conditions when “the ground is really warm and then the snow melts quickly” because “the plants do not have the same protection” as under a thick blanket of snow.
In this case, Scott is very clear that you need to cover your plants, “even the brassicas”. He explains that you can install a “long term seasonal extender” structure with tires and plastic sheeting, but if you don’t have one, act quickly.
If you are caught in a frost, you can minimize the damage by lightly spraying the foliage before the sun shines on them. Similarly, damage to potted plants can be mitigated by removing them from direct sunlight to allow them to “thaw” in the forgiving warmth of the shade.
What is best for protecting plants from frost?
To protect plants from frost, – tarpaulins, sheets, blankets or plastic sheets. The idea is to trap the warmth of the soil to protect your plants, especially spring flowers.
However, Scott has one very important tip so that your crop protection doesn’t make things worse. If you are using thin, clear plastic wrap, be careful not to let it touch the plant or the leaves will be damaged from contact with the frozen plastic. Use bamboo stakes or milk jugs to support the plastic wrap from your plants – ‘It’s only temporary, it doesn’t have to look good!’ he says.
When to remove the deposits? When temperatures rise – later in the day or when the ground warms up.
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Will a frosty night kill my plants?
A quick, light frost is unlikely to kill your plants, and you may only be able to mulch the plants to protect them from frost. Note, however, that young plants are very susceptible, so it’s always best to be on the safe side – older plants usually recover quickly.