Can You Wrap Potted Plants for Winterizing?

Winter Vulnerability

• Plants in containers, without the excellent insulation provided by garden soil, are particularly vulnerable to damage from cold winter temperatures. Roots of plants in containers are more exposed on all sides, and with fluctuating winter temperatures container soil thaws and refreezes -- sometimes causing plants to heave up, tearing roots and exposing them to drying winds. Temperature changes can crack containers, too. Top growth of plants is also vulnerable to storm damage and freezing.

The Best Protection

• Placing plants in a dark, cool -- but not freezing -- protected area is the simplest and best way to winterize them. If you don't have a suitable location, perhaps a friend or family member does. Leave plants outdoors as long as possible to prepare shrubs and trees for dormancy or winter "rest." A basement or an unused garage that can be kept between 40 and 50 degrees is ideal. Water plants once, when you tuck them in for their winter's nap, then leave them alone until winter is over. Come spring, take your potted plants outdoors, and water them well.

Planting Potted Plants

• Mike McGrath, "You Bet Your Garden" radio host, suggests planting potted trees and shrubs if plants need cold exposure or chill hours for fruiting -- because being in the ground offers greater insulation for vulnerable plant roots and crowns than any other alternative. If you can't bring yourself to remove them from their pots, then plant them pot and all -- assuming pots are plastic or wood, because terracotta or crockery will shatter in freezing weather -- and dig them up again in the spring. Water weekly until frost if there's no rain, and every month during winter dormancy if weather is dry.

Insulating Potted Trees & Shrubs

• Allow potted plants to "harden off" before winter by withholding fertilizer and avoiding any pruning -- which also stimulates new growth -- after midsummer. Water plants through fall. When plants lose their leaves after the first hard frost, place pots on solid ground and gently pull branches together and tie them. Water each shrub or tree deeply and mulch the soil with several inches of shredded leaves or straw. Make a cage from fence wire to surround the pot and top foliage; run a stake into the ground and attach the wire cage to it, for stability. Carefully fill the cage with shredded leaves or straw. Seal the insulation by wrapping the cage with burlap or shade cloth and tie it in place with twine. Waterproof the insulation by adding a final tucked-in layer of roofing paper or plastic, tied over the top. In spring gradually unwrap the tree, allowing the plant to acclimate.