How to Protect Your Plants From Frost

How to Protect Your Plants From Frost

As the summer comes to an end and the days start to get colder, there has been one thing on my mind:

"What is going to happen to my plants?"

First we need to have a look at what we are growing. There are three types of plant life cycles: annuals, biennials and perennials. Lots of flowers, fruits and vegetables are annuals - they complete their life cycle in one season, starting as a seed, germinating, blooming, going to seed and ultimately dying. Biennials develop roots, stems and leaves in the first year, then become dormant over the winter, and then develop their flowers, fruits and seeds in the second year. Like annuals, many biennial plants are also harvested in their first year, for example carrots and onions. Perennial plants live for more than two years. Most become dormant or die back in the winter, but keep on growing again the next spring. Examples of perennials include trees, rhubarb and blackberries.

So now we know that our annuals will die, and we have harvested the biennials, we need to decide what we will do with our perennials and the rest of the biennials that we want to keep for their seeds, flowers and fruits next season. How can we keep them alive through the harsh and unpredictable winter weather? We need a way to protect them.

1. Bring Them Inside

One easy solution for protecting your plants against a sudden frost is to temporarily move them inside until the frost has passed. This is ideal for potted plants, particularly smaller ones as they can be easily picked up and transported. The problem with this is that when your plants are inside, it can be difficult to provide sufficient light to keep them healthy. If possible, put them into a sunny spot such as a conservatory or windowsill.

While this is a quick and cheap way to keep your plants warm, it is not always possible to relocate all them. You may have a large amount of plants, they may be very big, or you may simply not have enough (sunny) space inside. Similarly, plants that are growing in the ground or in raised beds can't be moved. In this case, there are other options that you can use while keeping your plants outside.

2. Fleeces

Ah, the simple garden fleece. How can you go wrong? These are large sheets that can be used to cover your plants - think of a duvet for your plant bed. They come in all sorts of materials, sizes and weights, but most typical fleeces are made from polypropylene with a weight of 17g per square metre. They are great because they help to retain heat and humidity around your plants while also letting in air and water, which allows them to stay healthy as we transition into the autumn months.

There is also a type of horticultural fleece called a fleece jacket. These are just like the sheets but are shaped like a bag. Their shape makes them ideal for covering up single plants in pots and hanging baskets.

3. Cloches

Wait a minute, isn’t a cloche that silver dome that fancy waiters cover your food with? Well, yes, but this is different. Garden cloches are structures designed to protect your plants from the cold and from pests. They are more solid than garden fleeces, like little greenhouses for your plants. 'Cloche' is the French word for 'bell', and originally cloches for plants were bell shaped domes made from glass, designed to cover a single plant. While these traditional glass cloches are still available, there are now bell cloches made from plastic, as well as other types of cloches like longer or taller ones that can cover larger plants or multiple plants instead of just one.

One thing I love about cloches is that they are very portable. If there is a sudden frost, you can quickly cover your plant, and then it can easily be removed once it is no longer needed. Most cloches also keep out rain which, while could be seen as a negative, can help to prevent disease.

4. Tunnels

If you want to get really fancy, look for something like the Haxnicks Vigoroot Easy Table Garden. This raised bed contains a built-in self-watering irrigation system, and features its own removable polytunnel with adjustable vents.

5. Greenhouses

A greenhouse is a building made of glass that keeps your plants all nice and toasty. These are a great option, particularly for seed starting and growing plants that like a more tropical environment (much like me!). The issue is that they can be very expensive and you need a lot of space to have one. If price or size is an issue, do not fret - there are other options.

Cold frames and mini-greenhouses are ideal for balconies, patios, decks and smaller gardens. Cold frames are a lot like greenhouses, and are, in their most basic form, a box with a glass or plastic frame which helps to retain heat to keep your plants warm. These are great space-savers that still get the job done.

The Bottom Line

The end of summer can be a scary time for gardeners, but as the days get shorter and the temperature falls, this season’s work doesn’t need to go to waste. There are a huge amount of options for us to overwinter our plants (keep them alive over winter), whether that is as simple as bringing them inside the house or putting them in a conservatory, or a big, long term investment like constructing a greenhouse. Keeping our plants alive through the winter is a brilliant thing to do. Not only do we keep our plants that we have come to love so dearly over the course of the year, but we also give ourselves a head start for next year by skipping out the early development stages of our plants’ lives, and starting the season with mature plants. Starting the year with mature plants means, generally, a higher yield since they can focus more time and energy on producing what you want (i.e. flowers, fruit, etc.) and less on getting bigger - and who doesn’t want a higher yield?