Can perennials survive the winter in pots?
Updated: Mar 18
When the days start getting shorter and temperatures head south, it’s time to ask yourself: What do I do with my potted perennials for the winter?
I get asked this question a lot. And I’m here to let you know that perennials planted in containers and pots can survive the winter. Even in cold climates.
One of the major benefits of perennial plants is that they will die back and come again the following year. That goes for perennials in the ground and containers.
What’s better… Perennials overwintering in the ground or containers?
A perennial plant growing in the ground is more protected from severe cold (and the cycle of freezing and thawing) than one in a container. Ground-planted perennials also have better drainage. This is important in areas where colder temperatures also bring heavy rain (hi, Denmark).
If you’re growing native plants — plants that originated from your area — overwintering really isn’t an issue. They were born for that climate. Literally.
If you’re growing non-native plants, you’ll need to consider the lowest temperature that the plant can handle. Check with the garden center or website where you purchased your plant and find out what hardiness zone it belongs to.
Either way, with the proper care, keeping your potted perennials safe over winter is possible and easy to do.
3 ways to keep potted perennials safe over winter
Method 1 — Do nothing
If you’re growing native plants that are already flowering and thriving in their containers, then you don’t need to do anything. Your plants will naturally retreat and come back again in the next growing season.
What does the ideal winter container look like?
Your container should have good drainage. That includes holes in the bottom of the pot and a layer of gravel (or pieces of a broken pot) in the bottom. This keeps the roots from sitting in water all winter and rotting.
A layer of mulch or compost on top — around 2-3” (5-7 cm). This keeps the plant warm and will break down over the winter, filling the soil around the roots with delicious nutrients that your perennial will need once spring arrives. If you don’t have mulch, shredded leaves work just as well.
If you’re moving a perennial plant from your flowerbed to a pot, then choose a larger container for the winter. The extra soil surrounding the roots will help insulate and keep the temperature steady. Like with all pots and containers, make sure it has proper drainage and a layer of mulch or compost on top.
Remember to check each plant’s hardiness level. The soil in the pot won’t be able to stay as warm as the ground. That means that it will freeze sooner and thaw before the ground does. If your perennial is not able to handle thawing and freezing multiple times, then go with Option 2.
For the perennials that I treat this way, I do shift all of the containers to a corner of our terrace where there’s not much wind.
Move yours next to a house, shed or hedge. Keep them facing north if possible where they won't get the full power of the sun (if they face south, for example).
And I huddle my potted perennials together for warmth. And so they can keep each other company during the cold nights. (Not I think they actually talk together or anything. Or do I?)
Method 2 — Move plants indoors
If you’re growing borderline hardy plants (plants more likely to survive a cold snap in well-drained soil) or ones in small containers, I suggest moving them inside your garage, carport or greenhouse.
You won’t need to pay them much attention. Just make sure that they don’t dry out completely and you’re fine.
As soon as temperatures start warming up, move your perennial back outdoors and watch it come to life.
This also works if you’re not sure if your perennial can handle staying out all winter. Better safe than sorry.
Method 3 — Bury the container
This technique is one that I use a lot. I also talk about it as one of the best ways to grow invasive, non-native plants in this post.
Basically, you take the container and bury it in the ground. This keeps the root system insulated and safe from freezing temperatures.
Just like with all potted perennials, make sure the container has proper drainage and cover the plant with a layer of mulch or compost.
If you’d like, leave the plant in its new spot all spring, too. Otherwise, dig it out and put it back on your terrace when spring comes.
What kind of pot can you overwinter a perennial in?
It’s easy to forget about the pot or container, but it needs to survive the freezing winter temperatures, too.
Go for a frost-proof or freeze-proof pot. Most plastic pots work great and are light enough to be buried. Terracotta pots, while beautiful, are notorious for cracking in freezing temperatures.
In my experience, glazed ceramic pots handle the cold way better than unglazed ones.
Whatever pot you choose, make sure that your plant, mulch and compost aren’t waterlogged. What happens when water freezes? It expands. And crack goes your pot.
That applies to even the fanciest frost-proof container, too.
If it’s your first winter with potted perennials, and you’re not sure how your pot will do, simply move them into your greenhouse when temperatures drop or wrap them with a layer of insulation.
Quick guide for overwintering perennials in containers and pots
Perennials that are native to your area or hardy enough to survive temperatures in your area can be overwintered in pots, in the ground or inside a greenhouse or garage.
Whatever pot you choose, make sure it has great drainage.
Perennial plants need water throughout the winter, but don’t keep them fully wet.
There’s no need to fertilize during the winter. Wait until you see the plant start to grow again and then fertilize.
If you’re transplanting a perennial from the ground to a pot, go for a larger pot. More soil = better protection from the cold.
Huddle your containers for warmth and place them near a house, shed or hedge. Keep them away from the wind and use mulch or shredded leaves for extra insulation.
What plants can you put in my pots for winter?
Here are 8 container-friendly plants that you can put in your pots this winter.
1. Pansy (Viola x wittrockiana)
Height: 6-8 inches
Sun exposure: Full sun to partial shade
Soil type: well-drained
2. Primrose (Primula spp.)
Height: 6-8 inches
Sun exposure: Partial shade
Soil type: well-drained, moist
3. Viola (Viola spp.)
Height: 6-8 inches
Sun exposure: Full sun to partial shade
Soil type: well-draine
4. Heuchera (Heuchera spp.)
Height: 6-8 inches
Sun exposure: Partial shade
Soil type: well-drained, moist
5. Sedum (Sedum spp.)
Height: 6-8 inches
Sun exposure: Full sun
Soil type: well-drained, sandy
6. Hellebore (Helleborus spp.)
Height: 12-18 inches
Sun exposure: Partial shade
Soil type: well-drained, moist
7. Lenten Rose (Helleborus orientalis)
Height: 12-18 inches
Sun exposure: Partial shade
Soil type: well-drained, moist
8. Christmas Rose (Helleborus niger)
Height: 12-18 inches
Sun exposure: Partial shade
Soil type: well-drained, moist
Keep in mind that it's always best to check the specific requirements for the plant you have or plan to have in your garden. We all know that winter varies from country to country. The height can also vary depending on the environmental conditions.
Quick tips to protect perennials from frost
Mulch around the base: Mulching is a common gardening technique that involves covering the soil around plants with a layer of organic matter, such as straw, leaves, or wood chips. The layer of mulch helps to insulate the soil and prevent moisture loss, which protects the roots of the plant from cold temperatures. When mulching around the base of perennials, apply the mulch in a thick layer, at least 2-3 inches deep, but not so deep that it covers the crown of the plant.
Cover with a frost cloth: Frost cloth is a lightweight, breathable fabric that can be placed over plants to protect them from frost. It works by trapping heat close to the plant, creating a small microclimate that's warmer than the surrounding air. Frost cloth should be draped loosely over the plant and secured at the base to prevent it from blowing away. When selecting a cloth, look for a material that's specifically designed for plant protection and avoid using any plastic coverings, as these can trap too much heat and cause the plant to overheat.
Water before the frost: Watering the soil around perennials before a frost helps to insulate the roots and keep them warm. Wet soil actually retains heat better than dry soil. Watering around your perennials is a quick way to protect your plants from frost damage. Be sure to water the soil a few days before the expected frost, as this will allow the soil to absorb the water and for the plant to take up as much moisture as possible.
Move container plants: Like we've explained above, if you have perennials growing in containers, move them to a protected location during colder temperatures. Place them near a south-facing wall or under an overhang to help shield them from the wind and cold. When moving container plants, handle them gently and avoid jostling the roots too much. If you're moving them indoors, be sure to acclimate them slowly to the new environment to avoid any shock to the plant.
Prune back dead growth: Pruning back any dead growth on perennials before the first frost of the season helps direct the plant's energy towards healthy growth and also helps prevent disease and pest problems. Use a sharp pair of pruning shears to remove any dead or diseased growth, being careful not to cut into healthy tissue.
