The coldest season of the year can be hard on a tree, which remains exposed during all of winter's fury. Young or newly-planted trees are especially susceptible to the season because they lack established, extensive root systems and mature, thick bark.
By taking simple steps in fall, you can ensure your trees enter winter ready to weather whatever nature unleashes. To protect your new tree investment in its first winter, follow a simple checklist to take care of roots, trunk and branches.
Water – Young trees – especially evergreens – need adequate soil moisture through their first 2-3 winters. In regions where the ground freezes, consider irrigating during winter thaws, when water can actually penetrate soil.
Mulch – In late fall to early winter, place a 2-3-inch-thick layer of organic mulch that extends just beyond the tree's dripline. This is very important with newly-planted evergreens – both conifer and broadleaf. Avoid placing mulch directly against the trunk. Mulch accomplishes two key things: 1) insulates soil and tree roots against temperature extremes; and 2) slows water loss from soil. In cold zones where the ground freezes, wait until soil is frozen to apply mulch.
Stake – If your tree is in a windy spot or is top-heavy, consider staking. Use a method that allows the trunk to sway and move freely to enhance strong trunk growth. Attach tree to stakes using wide pieces of a strong, weather-resistant material, such as canvas or rubber.
No salt – In regions where winter brings ice, avoid using rock salt-based ice melt near new trees. Salt interferes with a tree's fine roots, inhibiting their ability to absorb the things a tree needs: water, nutrients and oxygen.
Irrigation bags – Remove irrigation bags from trunks before freezing weather arrives. Leave bags in place and you risk giving rodents cozy winter quarters and/or allowing ice to build up around the trunk.
Pests – Until young tree trunks develop hard, ridged bark, they're prized by gnawing rodents, such as rabbits and voles. They'll eat the bark, along with the green, growing tissue beneath. If damage occurs more than halfway around the trunk, you may lose the tree.
Protect trees from pests – You can spray repellents, but you likely will need to reapply following rain or snow. Repellents have varying rates of effectiveness. A more permanent solution is barricading tree trunks with plastic tree guards or quarter-inch wire cages. Be sure to install trunk protection above the snow line, or rodents will sit on snow drifts and chew bark.
Sunscald –Strong winter sun on the south and southwest sides of a tree can thaw tree bark by day. If night temperatures drop to freezing, thawed cells can rapidly freeze, causing rupturing and cracks in the trunk, which cuts off water to the tree top. This process is called sunscald. Prevent by wrapping trunks with crepe paper tree wrap or by painting trunks with diluted white latex paint. Commonly-affected trees typically have thin bark, including Ash, fruit trees, Honey Locust, Linden, Maple and Willow.
Branches And Foliage
Winter-burn – Newly-planted evergreens are susceptible to winter-burn, which results from the inability of the young roots to absorb enough water to prevent excessive water loss from winter winds. You can reduce water loss by spraying plants with an anti-desiccant (sometimes called an anti-transpirant) or by building a windbreak around plants. Hammer stakes into the ground and staple burlap onto them.
Broken branches – Heavy snow and ice can pile onto young branches and cause breaking. Prune broken branches as needed. When snow piles up, remove with a broom, using gentle upward movements. In snowy areas, protect upright evergreens, such as Cedar or Juniper, with special mesh covers, which you can find at garden centers.