That’s a Wrap: Winter Tree Protection

Shaun Moser, Conservation Garden Park

Fall is the best time to plant a tree. The cooler temperatures provide a better environment for new roots to grow into the surrounding soil. Regardless of when you plant a tree, make sure you protect them during the upcoming winter. Young trees have tender, thin bark that is more susceptible to damage than older or mature trees.

Two of the more common types of damage that occur in the winter to young trees are southwest winter damage (or sun scald) and damage from animals. Southwest winter damage happens when daytime temperatures rise and cause cell activity to increase in the tree during the winter. When warmer temperatures are immediately followed by freezing temperatures, such as when the sun goes behind a cloud or sets, the sudden change in temperature can cause a wound to occur on the tree. While many young trees are permanently damaged by this, some recover over time.

Animal damage usually happens from chewing or rubbing. Voles, mice, and rabbits generally cause chewing damage, usually at the bottom of the trunk. Rubbing or stripping of the bark is most often done by deer. This can girdle or destroy a young tree, and deer can target young trees as early as September 1.

The best way to protect your newly planted trees from southwest winter damage is to either paint the trunks white (as is commonly done in fruit orchards) or wrap the tree trunks. This reflects the winter sun’s heat from the young trunk and greatly reduces the chances of damage. The most common tree wrap is a fabric/paper that comes in rolls that you can roll around the tree from the bottom of the trunk up to where the first branches begin. You can also buy plastic tree wrapping material that looks like a white tube. This is what we use most commonly at Conservation Garden Park. We find this easier to install and easier to reuse. It is best to wrap a new tree for its first three winters for best results, and unwrap it each spring. Whatever you do, be sure the wrap comes off for good at the end of year three—leaving it on for longer will hurt the tree in the long term.

Some of these tree wraps can help to protect the trunk from animal damage, but the best way to protect a young tree from being destroyed by a deer is to put a metal cage around the tree starting September 1. This is what we must do at Conservation Garden Park because there are deer in the Garden every night. Simply wrap the metal around the tree and secure it with zip ties, and voila! Instant deer protection.

You still have time this fall to put in a new tree, and if you follow these tips, you will give it the best chance of surviving to maturity without damage. Once the tree is 3-4 years old it will start developing a much stronger, mature bark and you won’t have to worry about winter damage and can enjoy your tree for many years to come.