Trees, Shrubs, Winter Protection, Frost

Pine wrapped with weave mat and rope for snow protection in winter. (Photo: Shutterstock).


Carol O'Meara, Colorado State University Extension

Carol O’Meara, Colorado State University Extension

LONGMONT – Before you turn your thoughts to indoor entertaining, take advantage of the next warm day to put your trees and shrubs to bed for the season. With a little bit of wrapping and a plan to winter water, your woody plants will weather the worst winter can throw at us.

In Colorado that means a rollercoaster ride of warm days and cold nights. Young, thin barked trees exposed to the sun risk having trunk cells warm, losing their cold protection. As nighttime temperatures plunge, these cells freeze and burst, resulting in sunscald on the trunk, an area that will be prone to disease in summer.

Sapling fruit trees are vulnerable to sunscald, as well as lindens, honeylocusts, ashes, oaks, maples, and willows. Protect them for the first two to three years they’re in your landscape by wrapping them with tree wrap in early in November.

Wrap from the ground upward, overlapping each layer over the lower one by one-half-inch until you reach the lowest branch. Use tape to hold the wrap in place, making sure the tape doesn’t stick to the trunk.

Water is critical for all woody plants in winter, keeping them cold hardy as well as preventing dieback of branches and roots.  Water them once every four weeks if we’ve been dry. A quick way tell if you need to water is to measure every snowfall at your house, write it on the calendar and add it up every four weeks. If the total isn’t 12 inches of snow, water as soon as the day warms to 45 degrees or more.

Make the chore of watering on chilly days easier by laying a soaker hose around the tree now, while the weather is warm.  But don’t place it up against the trunk – lay it at the drip line, the area one foot inside the tips of the branches. Hook up your hose on the days to water, then unhook it before nightfall.

Pruning of shrubs usually takes place in very early spring or just after the shrubs bloom, so there’s no need to plan for pruning in fall. Keep evergreens healthy by leaving the pruners in the shed – if sheared in fall or winter, they lose water in our dry winds, and their foliage turns brown.

If you have fruit trees, protect them from voles. These small, mouse-like creatures are a danger to apple, pear, or peach trees because they strip bark from roots and trunks, girdling or killing the plant. Grasses or ground covers planted near the base of trees provide hiding places for voles, and predators have a hard time hunting them.

Remove plantings near trunks and clip grasses short to leave the area exposed (or mulched with wood chips). In extreme cases, try keeping the voles out by surrounding trees or shrubs with stout, ¼ inch wire hardware cloth.  This should be buried six inches below the surface and stand at least 18 inches tall.

By Carol O’Meara. Colorado State University Extension, together with Boulder County Parks and Open Space, provides unbiased, research-based information about consumer and family issues, horticulture, natural resources, agriculture and 4-H youth development. For more information contact Colorado State University Extension at the Boulder County Fairgrounds, 9595 Nelson Rd., Box B, Longmont, 303.678.6238, e-mail or visit