How to Protect Outdoor Plants and Pots Before Deep Winter Hits

Winter takes a toll on gardens. Cycles of freezing and thawing make the soil heave, exposing plant roots to cold air. Ice and snow can break branches, and dry winds dehydrate leaves and stems. Temperature changes can make bark spilt, and salt runoff from roads and driveways often damages or kills plants.



Winter weather is also rough on pots and planters. Frostproof or weather-resistant pots should be able to survive outdoors, if hailstones don't batter them and winds don't blow them around. Unfortunately, containers made from other materials can absorb moisture, freeze and crack. Use our easy steps to protect pots and potted plants from winter weather, and read on for special winterizing tips.

How to Protect Outdoor Potted Plants In Winter

Planning to leave your pots of cold-hardy plants outdoors all winter? Here's what you need to know.

Some Plants Really Should Be Moved Inside

Some tender perennials, such dahlias, should be removed from their pots (or the ground), allowed to dry and stored in a cool, dark place like a basement until warm weather returns. Do a little research to find out which perennials should be lifted, and which ones can overwinter outside.

Elevate and Cluster Potted Perennials

If possible, elevate your potted perennials off the cold, moist ground. Group them together with the most cold-resistant plants on the outside. Put them near a wall or fence that can serve as a windbreak, or near a south-facing wall of your home where they might get some radiated warmth. (Move them further away from the wall if intense sunlight threatens to make the soil freeze and heave.)

Insulate Potted Plants

Insulate the potted plants with mulch, such as shredded leaves, bark chips or straw.

Choose the Right Cover for Evergreens or Other Hardy Perennials

To protect evergreens or other hardy perennials that grow all winter, choose a cover that lets in air, light and water while shielding them from heavy snows that can cause damage and desiccating winds that can make them look burned and scorched.

More Winterizing Tips, Based On Your Type of Pot

Cold-Hardy Plants In terracotta, Clay or Standard-Glazed Ceramic Containers

It's best to move winter-dormant perennials in these less durable containers into an unheated garage, basement or shed for the winter.

If they must stay outdoors, wrap the pots in bubble wrap, burlap, old blankets or frost-proof cloth and keep them in a sheltered spot.

Top the plants with mulch, and, for additional protection, surround the pots with more mulch or hay bales. Some gardeners wrap and/or cover their dormant, potted perennials with plastic, but that doesn't allow air to circulate and can trap too much moisture and condensation inside. Plastic can also damage the plants if it touches them when the sun hits it.

Cold-Hardy Plants In Metal Pots

Since metal conducts cold faster than other materials, you may want to remove cold-hardy plants from their metal pots and insert pot liners or mulch for insulation. Then replace the plants and soil, and wrap and/or cover them with burlap, a tarp, old blankets or frost cloth.

Cold-Hardy Plants In Frostproof, Glazed Ceramic, High-Quality plastic, Resin or Riberglass Pots

Wrap and/or cover these containers in burlap, frostproof cloth, old blankets, a tarp or bubble wrap.

How to Protect Empty Outdoor Pots

Clean and Dry Pots

If you’re not going to overwinter your plants, take them out of their pots and wash and dry the pots thoroughly. Don’t leave any soil inside that can hold moisture and freeze.

Store the Pots In a Sheltered Area, If Possible

For best results, store the empty pots in an unheated indoor area, like a shed, garage or basement. If they have to stay outside, make sure they have drainage holes so water can't collect in them and turn them upside down. Put them in a sheltered place, like on a covered deck, or store them near a wall or shed that will act as a windbreak and help moderate temperature swings.

Stack or Cluster Pots Together

Like people in a huddle, groups of pots help hold in the day's warmth. Use cardboard or burlap between them, if needed, to prevent scratching and chipping, but don’t block the drainage holes if they're outside.

Elevate the Pots on a Wooden Pallet

This way they won’t freeze and stick to the cold, moist winter ground. No pallet? Put them on pot feet, small blocks of wood, rocks or plant stands.

Cover Empty Pots Stored Outdoors

Use frost blankets, burlap, bubble wrap, old blankets or heavy-duty plastic. Breathable materials are a good choice, because they allow air circulation and discourage moisture from accumulating. Hold the covers down with bricks, rocks, garden stakes or landscape staples so winter winds don’t blow them off.

Tips for Protecting Different Kinds of Empty Pots

Different kinds of pots need special winter protection. Porous pots, for example, can absorb moisture and crack unless they're protected with water-resistant coverings or wrappings.

• Resin and fiberglass pots: These are excellent containers for outdoor use, because they’re usually durable, frost-resistant, non-porous and crack-resistant. For more protection, apply a wax coating to them or insulate them with straw, bubble wrap or burlap.
• Plastic pots: High-quality plastic pots are more frost-resistant than clay or terracotta containers, but they can eventually become brittle and fade in the sun, so it's a good idea to wrap and/or cover them.
• Wooden planters: Apply a wood preservative to shield these containers and cover them with a water-resistant material. Elevating them not only keeps them from freezing to the ground, but also helps prevent rotting (although woods like teak, redwood and cedar are naturally rot-resistant).
• Ceramic pots: If you must leave relatively fragile ceramic pots outside, turn them upside down, elevate them and wrap and/or cover them with a waterproof material. Most ceramic containers with frostproof glazes should hold up to winter weather, but their glazes and paints can crack or flake. Thermal shock--that is, sudden temperature changes--can also break ceramics, especially if they have a standard glaze.
• Metal containers: Use a waterproof sealant or anti-rust paint to guard against rust. After it dries, cover metal planters.
• Concrete, terracotta and clay pots: These porous planters absorb moisture, so consider applying a waterproof sealant before wrapping and/or covering them.
• Fiber cement pots: Made from cement, sand and fiberglass, these containers are typically waterproof, frost-resistant and less prone to cracking than kinds of pots. Cover them for maximum protection.

Caring for Cold-Hardy Potted Plants In the Winter

Check your potted perennials periodically in case they need water, but don't add enough to make the soil soggy; wet soil can freeze, expand and crack their containers. The best time to water is during the day, when the temperature is above freezing, or just before cold, dry winds or freezing temperatures are expected.