How to Keep Your Plants Warm This Winter

With the winter months fast approaching, many gardeners start worrying about how to protect their plants from the cold weather. Freezing temperatures can damage and even kill many plants, but there are things you can do to help your plants survive and thrive through the winter. In this article, we’ll go over some of the best tips and techniques for keeping your plants warm when the mercury drops.

Move Plants Indoors or Under Cover

One of the simplest ways to protect plants is to bring potted plants inside and overwinter them indoors. You can place them in a sunny window where they’ll continue getting light. For plants still in the garden, move potted plants and container gardens into an unheated garage, shed, or under a covered porch. This will help shield them from wind, rain, ice, and snow. If you have a greenhouse or cold frame, you can move plants under cover too. Even just placing something over plants like a cloche or overturned bushel basket can make a difference.

Use Row Covers and Mulch

Row covers like fabric or plastic sheets can be placed over garden beds to trap heat and protect plants Make sure to anchor them properly so they don’t blow away. You can also heavily mulch around perennials, shrubs, and trees. A thick layer of shredded leaves, wood chips, or straw will help insulate the soil and protect roots It’s best to mulch late in the fall after the ground has frozen to prevent rodents from hiding under it. Rake mulch away from tree trunks and stems to prevent rotting.

Prune and Prep Plants

Pruning away dead wood helps prevent disease and damage from snow or ice accumulation. Pruning certain plants like butterfly bushes and mums late in fall can encourage new growth that is more vulnerable to cold. Stop fertilizing 6 weeks before your first frost date; new growth triggered by fertilizer will also be prone to damage. Finally, make sure plants are well-watered before the ground freezes. Dry soil and plants are more susceptible to winter kill.

Protect the Roots

The roots of your plants are just as vulnerable to freezing and damage as the above ground parts. You can wrap above ground roots or pipes in insulation or bubble wrap. Install plastic or vinyl tree guards around young trees for protection. Place burlap around the base of plants to protect from sunscald. And if a hard frost is forecasted, water your plants well to insulate roots and delay freezing. Just make sure there is ample drainage first.

Use Lights to Extend Growing Season

Outdoor lighting and grow lights can help lengthen your plants’ growing season. Some full spectrum LED grow lights can even be used outside to supplement natural sunlight on cloudy days. Just be sure any outdoor electrical fixtures and wiring are rated for it. You can start seedlings early indoors under grow lights too. Once sprouted, move them into a greenhouse or cold frame to transition outside.

Create a DIY Greenhouse or Cold Frame

A DIY hoop house, greenhouse, or cold frame is not that difficult to make and can drastically extend your growing season. All you need are some PVC pipes, plastic sheeting, and lumber to create a framed structure. There are many free DIY greenhouse plans online to follow. Make sure any greenhouse has adequate ventilation, and roll up side plastic or windows during the day. Use a thermometer inside to monitor temperatures.

Use Heating Devices Sparingly

Space heaters, heat mats, and other devices can sometimes be used to provide additional warmth on especially cold nights. But anything that gives off heat in an enclosed space can quickly burn plants. Never leave heaters unattended or operating when you are asleep or away. Make sure plants are not directly touching hot surfaces. And always check that any electrical devices used outdoors are rated for it and have GFCI protection.

Insulate Pots and Containers

Terra cotta, concrete, and ceramic pots pull away heat from the soil and plant roots. You can help insulate them by double potting in a slightly larger pot. Place polystyrene packing peanuts, crumpled newspaper, or other insulating materials in the gap between pots. Wrapping the outside of pots in bubble wrap, burlap, or foam noodles will also help retain more warmth inside. Make sure drainage holes are not blocked.

Choose Cold Tolerant Varieties

When planning your fall garden or making plant purchases, look for plant tags or descriptions listing cold hardiness information. Selecting plants rated for your USDA plant hardiness zone or lower will give you the best chance at overwintering success. There are many beautiful shrubs, perennials, and woody plants that can withstand cold winters so do your research.

Cover and Care for Tropical Plants

Tropical plants like bananas, palms and elephant ears will not survive outdoors in winter in cooler climates. They should be brought into a heated greenhouse at minimum if they can’t come indoors. Make sure tropicals get adequate humidity and warmth indoors near sunny windows. Limit watering in winter. Before bringing tropical plants in spray them down outdoors to remove any insect hitchhikers first.

Use Physical Barriers for Wind Protection

Strong winter winds can quickly dry out and damage plants. Install fences, trellises, burlap barriers, or stake plastic sheeting around gardens to reduce wind. Keeping plants grouped together also helps buffer from drying winds. Move outdoor container plants together in a protected area, and sink pots into the ground or surround with bagged soil for added insulation.

Monitor for Snow Load Damage

Heavy wet snow can break branches damage structures, and crush plants. Use brooms to gently remove snow from delicate plants or trees if it accumulates faster than it melts. Consider staking tall perennials and placing lumber supports under shrubs to prevent bending and breakage. Brush heavy snow off greenhouse or cold frame covers too.

Water Before and During Winter Dormancy

Plants still need moisture through winter but generally less than in spring and summer. Water container plants periodically if soil dries out. Use just enough water so it penetrates the soil without creating runoff during cold snaps. For gardens, do a deep watering in fall before the ground freezes. During winter thaws, water if there are more than 12 frost-free days to replenish moisture.

Don’t Prune Too Late or Too Early

Pruning stimulates new growth, so avoid doing it late in fall just before dormancy or too early in late winter before the last frost. The exception is removing damage from heavy snow or ice. Make a habit of cleaning up beds in early fall and waiting to prune in early spring once you know the worst of winter has passed.

Check Evergreens for Snow Damage

Evergreens can collect heavy snow that doesn’t always shed easily in their branches. Use a broom to gently remove snow before it freezes after an ice storm or heavy wet snow. Check for any split branches or damage after major storms. It’s better to selectively prune damaged parts than lose the entire plant.

Watch for Animal and Pest Damage

Rodents, deer, and insects can damage dormant plants in winter. Monitor for chewed bark, gnawed stems, and severed roots. Mice and voles often nest under mulch, so only apply mulch after several hard frosts. Coat tree trunks with vaseline or wrap with hardware cloth to deter mice and deer rubbing. Spray repellent like capsaicin, garlic oil, or white vinegar around plants susceptible to rabbit or deer damage.

Remove Dead Foliage and Plants

As plants die back in fall, make sure to clean up and remove any fallen leaves or decaying plant matter. Dead foliage left laying on beds can harbor fungal disease spores and insect eggs that will emerge next season. It also blocks sunlight and airflow from getting to plants. Compost healthy plant material and discard any diseased plants or leaves.

Check for Snow Mold and Freeze Damage

Once winter ends, assess all your overwintered plants for any signs of snow mold or freeze injury. Snow mold appears as gray or tan fuzzy patches on leaves and stems. Prune out affected areas. Freezing damage usually shows up as wilted, watersoaked foliage that eventually turns brown. Wait to see how plants recover once they break dormancy before pruning freeze damaged parts.

Protecting your plants through a long winter doesn’t require complicated or expensive solutions. Just a bit of preparation and TLC will go a long way towards ensuring your plants remain healthy. Implement some of these tips to keep your plants cozy and warm until spring arrives again.