A savvy gardener knows how to plant a garden that can survive all seasons, including winter, and this is true for their potted plants as well.
However, when the typical winter turns into something colder and harsher than anyone expected, your plants will be the first to suffer.
Most plants won’t tolerate a sudden frost or freezing conditions, and you don’t want all of your hard work to go down the drain just because of some unexpected weather.
When exposed to these kinds of temperatures, most plants will be damaged in their cells and many will die, so it’s a gardener’s worst nightmare.
How do you protect potted plants from frost, then?
There are a few methods available to save your plants from the extreme cold like covering them, adding much around the base, storing them inside during winter, and implementing a greenhouse at home.
The best method will depend on the quantity and type of plants you have as well as how much effort you’re willing to put into your potted garden.
Potted plants have the luxury of being able to move freely wherever you need them to go, so you have this working in your favor at least. To ensure your plants survive the winter and sudden bouts of frost, check out our list of ideas for how to keep them protected.
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Why Does Frost Hurt Plants?
When a plant is exposed to freezing conditions and develops frost, it gets deep down into the plant’s cells.
This then shrinks the plant’s cells which forces water in between them that freezes, causing the plant to develop frost and ice crystals to form inside and outside of the plant.
In some cases, frost that only occurs briefly won’t have any long-standing damage.
When the temperature rises again and the plant starts to thaw out, the cells absorb the water using osmosis, and if it’s done quickly enough there’ll be no harm done.
However, when the thawing is slow, as happens sometimes in winter, the plant will develop frost burn because they have no access to water, and they will usually die.
Even if you predict a short snap of frost, it’s good to have a backup plan in place for your plants. Potted plants have the added benefit of being movable, unlike a fixed garden bed, so there are more options for keeping them safe even in freezing conditions.
Methods for Protecting Potted Plants
Potted plants won’t survive long in harsh winters with frost, so it’s up to us as their owners to have measures in place to protect them.
These are some common methods for reducing the impact of frost on potted plants and ensuring they sustain through even the coldest winters.
Covering plants
Cover your plants with a soft, porous material like hessian to keep them safe from frost.
Avoid anything like plastic as it can develop moisture inside which leads to a faster build-up of frost.
Adding mulch
Protect the base of your potted plants with mulch so it’s harder for the frost to get in.
For the best results, avoid anything made of organic materials because it’s more likely to have larger spaces where frost can develop, instead opting for gravel.
Keep them grouped together
Just as humans huddle together for warmth in winter, so too can your plants. If you’ve got a group of potted plants that live outdoors, you can keep them close to each other to feed off their warmth and protect each other from the frost.
Keep them inside
Many potted plants live happily indoors but not all of them are built for these conditions.
If you have plants that usually live outside but winter is coming, consider moving them indoors near a well-lit window until the harsher weather moves on.
Look at airflow
The position of the pots will dictate how much frost they receive, so you’ll need to spread them out so they’re not blocking the flow of cold air at the ground.
Air that moves upward is usually colder, which causes frost, so keep the base of your pots clear from things like other plants and weeds.
Water plants regularly
You might assume that watering plants during winter will only lead to frost, but the opposite is true.
Frost loves dry soil and will reach your plants easier than if the soil is kept moist and regularly watered.
Planning for Frost
In addition to having your backup methods for plants when frost hits suddenly, you can also do a few things in advance that will help.
Put these into play when you live in a cold climate to give your plants a better chance of survival.
Use seaweed sprays
Using a fertilizer or booster that contains seaweed can be a good way to protect potted plants from freezing in the future.
Seaweed is great at strengthening the cell walls of a plant so even if it’s exposed to frost, it will be strong enough to deal with the damage done.
Don’t prune in winter
Avoid the urge to prune back your potted plants in winter and spring.
When the sap flow increases as you prune, this will lead to further frost damage and will kill your plants faster.
Choose the right plants
Rather than picking a plant because it looks good, choose one that suits your climate and you’ll have fewer issues.
A frost tolerant plant will be much better for these harsher conditions and will require less maintenance when winter comes around.
Use a greenhouse
A greenhouse can be as small or elaborate as you like, and it’s a great way to keep temperatures warm and cozy inside, especially during winter.
These structures trap the heat in and prevent frost from entering, so it’s worth looking into if you’re ready to take your gardening to the next level.
Don’t cultivate in winter
Leave any turning of soil or cultivation until the weather is warmer as this can lead to frost buildup.
Recently cultivated soil features lots of holes and spaces where cold air can travel and be trapped, turning your plant’s leaves to frost sooner than usual.
Map out your garden
With some savvy planning and an understanding of where hot and cold parts of the garden are, you can use these to your advantage.
These areas are referred to as microclimates and if you can establish where the warmer parts are, you’ll be able to store the more sensitive potted plants there.
Frost Free Plants Are Happy Plants
Most plants love nothing more than sunshine and good weather, so when winter rolls around they’re likely to suffer a little.
If frost is common where you live or the temperatures regularly get down to freezing, there’s a lot you can do to be prepared and keep your plants frost-free.
As well as having some backup measures to put in place when frost is predicted, you can make changes to your gardening set up to minimize the damage.
With both tactics working for you, your plants will come out the other side of winter happy, healthy, and free from frost damage.
Related Questions
Frost is one of nature’s biggest enemies for the potted plant but as their savvy owner, you’ll have everything you need to keep them happy.
If you’ve got other questions about potted plant gardening and common issues that people face, check out these FAQs to see if we can answer them.
Repotting should be done every 12 to 18 months depending on the size of the plant and its growth rate.
Repotting can simply mean changing the soil and doesn’t necessarily require you to put the plant in a new pot unless it’s outgrown its last one.
Potting soil varies dramatically between products and the way it’s stored can also impact its lifespan.
An unused bag of potting soil lasts around six months, but when it’s used in a potted plant, it should keep its quality for a year or two before needing to be repotted and replaced.
Adding fertilizers is important for keeping the nutrient content up for the plants that make this soil their home.
The root rot fungus will usually contaminate soil as well as the plant that is affected, but you may be able to reuse the soil when the plant is gone.
To do so, mix the soil with water and then boil it before drying it out.
This should destroy any remaining trace of the root rot fungus and make the soil healthy again.
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