Guard your young fruit trees before winter sets in

That young apple or plum you babied all summer can lose bark to winter sun, or get girdled by a vole. Both are cheap to prevent, and November is the time.

Two winter problems, one cheap fix

Sunscald shows up as sunken, dried or cracked dead bark, usually on the south or southwest side. The winter sun warms the bark awake, then a cloud or building blocks it and the tissue chills and dies, per University of Minnesota Extension.

Young, newly planted and thin-barked trees (cherry, crabapple, plum) are most at risk.

Wrap the trunk in a white guard, not a brown or black one, because the dark ones soak up heat.

Illinois Extension says the goal is not to keep the trunk warm but to let it get cold and stay cold. Wrap from the soil line up to the first branches. Minnesota says keep wraps on newly planted trees for at least two winters and put them on in fall.

Newly planted trees keep their wraps on for at least two winters.

Keep the voles and rabbits out

Voles can girdle the bark, and young trees are most at risk, according to University of New Hampshire Extension. Its advice:

• Use 1/4 inch mesh galvanized hardware cloth, at least 18 inches tall.
• Bury it 1 to 4 inches in the ground.
• Clear leaves out of the guard, and make sure you can see the base of the tree through it.

For rabbits, Iowa State says fencing around vulnerable plants usually needs to stand 24 to 36 inches tall so they cannot reach over after heavy snow. After a big storm, check, and clear some snow if you need to.

Pull mulch back from the trunk by several inches, because voles and field mice avoid open ground (Illinois Extension).

Bottom line

• Wrap young trunks in white guards in fall and remove them in spring, per University of Minnesota Extension.
• Ring the trunk with buried 1/4 inch hardware cloth against voles, per UNH Extension.
• Pull mulch back several inches from the trunk, per Illinois Extension.

Your zone

• Zone 3-4: University of Minnesota Extension says to wrap young trees in fall and run 1/4 inch hardware cloth rabbit cylinders 18 to 24 inches above the anticipated snow line.
• Zone 5-6: Iowa State advises fall trunk wraps and rabbit fencing 24 to 36 inches tall; UNH Extension says plastic tree wraps go on in November.
• Zone 7-8: Utah State University Extension says to wrap susceptible trees with white tree wrap in late fall and remove it the next spring.
• Zone 9-10: In St. Lucie County, UF/IFAS Extension says to wrap young citrus trunks up to 2 feet around the base, which defends the graft against freezing.

Sources

• University of Minnesota Extension, "Protecting trees and shrubs in winter" - https://extension.umn.edu/garden-and-home/yard-and-garden/lawns-and-landscapes-in-minnesota/protecting-trees-and-shrubs-in-winter
• Iowa State University Extension, "Protecting Trees and Shrubs in Winter" - https://yardandgarden.extension.iastate.edu/how-to/protecting-trees-and-shrubs-winter
• Illinois Extension, "Winter Protection for Young Trees" - https://extension.illinois.edu/blogs/over-garden-fence/2014-12-26-winter-protection-young-trees
• University of New Hampshire Extension, "How do I prepare my backyard fruits for winter?" - https://extension.unh.edu/blog/2020/10/how-do-i-prepare-my-backyard-fruits-winter
• Utah State University Extension, "Sunscald Injury or Southwest Winter Injury on Deciduous Trees" - https://extension.usu.edu/forestry/publications/utah-forest-facts/021-sunscald-injury-or-southwest-winter-injury-on-deciduous-trees
• University of Florida IFAS Extension St. Lucie County, "Tips to protect citrus trees from cold weather" - https://blogs.ifas.ufl.edu/stlucieco/2023/01/13/tips-to-protect-citrus-trees-from-cold-weather/ Photo: Apple Tree with Fruit in Winter East Hampton New York by Hayden Soloviev, CC BY 4.0, via Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Apple_Tree_with_Fruit_in_Winter_East_Hampton_New_York.jpg Photo: Tree shelters in a forest, Emmendingen, Baden-Wurttemberg, Deutschland, 2015-04-10 162646 by 7C0, CC BY 2.0, via Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Tree_shelters_in_a_forest,_Emmendingen,_Baden-W%C3%BCrttemberg,_Deutschland,_2015-04-10_162646.jpg