When freezing temperatures arrive, many gardeners worry whether their potted perennial plants will survive the cold. Even if a plant is hardy in your growing zone, it can still struggle when kept in a container. That’s because the roots are above ground—exposed to more cold, wind, and temperature fluctuations than plants growing directly in the soil.
A helpful rule of thumb is to choose plants hardy to two zones colder than your area if you expect them to overwinter outdoors in containers without protection.
Fortunately, there are several effective ways to help your potted perennials make it through the winter. Below are simple, reliable methods to keep your plants safe until spring.
Move Potted Plants Indoors
For some plants—especially tropical or desert species—bringing them inside allows them to continue growing through winter. For example, I bring my potted white sage and thyme indoors before the first frost. Placed in a sunny spot, they stay green and healthy all season long.
Other perennials benefit from going dormant, and for those, a cool and protected place such as a garage, basement, shed, or cold frame is ideal. Water only when the soil is dry to the touch; dormant plants need very little moisture and are susceptible to root rot if kept too wet.
It’s always best to research the specific varieties you’re growing to understand their needs…but don’t be afraid to experiment. Some plants thrive indoors, while others prefer a quiet rest in a cooler location.
Protect Perennial Plants with Straw or Mulch
If your pots are too large to move—or your plants are borderline hardy in your zone—you can protect them outdoors by insulating the containers.
Cluster pots close together and place them against the south side of a building to reduce wind exposure. Then:
- Cover the soil surface with several inches of straw or mulch.
- Surround the pots with straw bales for insulation.
- Wrap containers in bubble wrap or burlap, which helps reduce wind damage (especially for evergreen shrubs).
Pro Tip:
You can extend the growing season for cold-tolerant vegetables like kale, carrots, and chard by surrounding their bases with a thick layer of straw or mulch.
Plant Potted Perennials in the Ground
Another highly effective method is to bury the entire pot in the ground. This is more work, but the soil acts as natural insulation, protecting the roots from wind and extreme temperature swings.
Dig a hole large enough for the container, place the pot inside, and cover it with soil. Add a thick mulch layer on top and water well before the first freeze.
Protecting Empty Containers for Winter
If you have containers that held annuals, you won’t need to overwinter the plants—but you should protect the pots.
Containers made of ceramic, terra cotta, porcelain, clay, and other fragile materials can crack during winter temperature fluctuations if left with soil inside.
To protect them:
- Remove the old soil and dead plants.
- Rinse the pots thoroughly and allow them to dry completely.
- Stack them upside down in a garage, basement, or shed.
Stored properly, they’ll be ready to go when spring planting returns.
Protecting Your Potted Plants This Winter
With these overwintering strategies, your potted perennials will have the best chance of surviving the cold and thriving again in spring. Whether you move them indoors, insulate them with straw, or bury them in the ground, each method helps protect the vulnerable root systems from winter stress.
Once your plants are tucked in and your containers stored away, all that’s left to do is relax, stay warm, and enjoy the peaceful quiet of winter.
Download our Overwintering Potted Perennial Plants – Checklist
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