ENVIRONMENTAL NOTES – Cold-weather landscape care

Winter feels as though it's already here, and this is an important time to get your landscape ready for the cold weather ahead. There are several easy things that you can do to help your trees, shrubs and lawn survive the winter and be in shape for the growing season.

Trees are big investments in the home landscape, and preparing newly planted trees for winter is particularly important. Supplying trees and shrubs with adequate moisture before the ground freezes is important to avoid winter root injury. If the soil is dry, water trees by placing a garden hose near the tree and let the water run out gently for about two hours to thoroughly water the tree. Young boulevard trees need water too, so remember them when you are watering.

Newly planted trees may need to be wrapped with tree wrap to protect the bark from cracking as the sap freezes and thaws on warmer winter days. Most newly planted trees require two winters of trunk protection; however trees with thin bark, such as maples, linden and crabapples, may need five or more winters of trunk protection. Tree wrap should be put on in the fall, and taken off in spring after the last frost.

Mulching trees and shrubs with woodchips is another helpful fall activity, as it moderates soil temperature and will prevent the ground from heaving during spring freeze-thaw cycles. Woodchip mulch should be applied to a depth of 4 to 6 inches in a 3- to 6-foot diameter circle around the tree. Mulch should not be placed right up to the trunk, as this will provide a good space for damaging insects to live.

Woodchip mulch is still available, free of charge, from the Minneapolis Park and Recreation Board's Forestry Department. Woodchip piles are located throughout the city. For a location near you call the Minneapolis Park and Recreation Board at 370-4900 and ask for the Forestry Office, or check the Park Board website at www.minneapolisparks.org.

Mulching garden beds provides the same benefits for perennial plants as it does for trees. Using leaves is an inexpensive way to mulch gardens and makes good use of leaves instead of bagging them and having them hauled away. It is best to shred the leaves before they are put on plants. Shredded leaves provide better insulation, will break down faster in the spring and will not mat down on the plants. Leaves can be worked into the soil in spring to add organic matter and improve soil health.

Mulched leaves can be used on your lawn, too. Before mulching, leaves should be no more than 2 inches deep on your lawn. It does not take a very heavy layer of leaf mulch on the lawn to smother the grass. If you do have a large accumulation of leaves on your lawn, compost some of them or put them on gardens as mulch. Whether you add a mulching attachment to your power mower or use a regular rotary mower, mow over the leaves several times until they are well chopped. Make sure that leaf mulch left on the lawn is not left in clumps and is only applied as a light layer.

Leaves from trees with leaf diseases such as apple scab, anthracnose or leaf spot should not be used. Instead, they should be removed or destroyed to prevent disease organisms from over-wintering and causing possible re-infection of new leaves next year. If your lawn has a problem with thatch, first take care of this problem before you add leaf mulch to the lawn.

Each of these steps will help to ensure that you have a healthy, green and growing landscape when next spring comes around.