I recently ran into a good friend who lives on the edge of a park. She loves her acre of land and has a favorite reading spot under a large tree where it's shady, cool and private.
This retreat is anchored by impressive, velvet green arborvitae. Since the weather began getting colder, she hadn't spent time there for a few weeks. But on one recent, Indian summer weekend, she headed to her favorite spot only to find chunks taken out of her arborvitae up to about 4 or 5 feet. Just a tuft of green remained at the top of each plant.
"The deer ate my arborvitae to almost nothing and rubbed ¾ of the bark off with their antlers," he says.
The trees came back in the spring and are still around today. "They weren't the prettiest plants in the world after that happened, but they were pretty resilient and survived the attack," he says.
To share advice with my friend, I asked Christensen for a few pointers on keeping a harmony between deer and trees in the landscape.
Unfortunately, the list is short of trees that deer won't eat … and even then, those plants are deer resistant, not deer proof. Deer definitely love Japanese yew, so avoid planting those if you have a large deer population in your area, Christensen says. "Sometimes, deer seem to avoid Western arborvitae planted on the East Coast and vice-versa, so that's a good trick," he adds. "And they don't seem to like some wetland plants or button bush. But, really, deer will eat anything if they are desperate enough, so we experiment with what we plant in deer-prone areas just like everyone else."
For folks who love their trees and have a big deer problem, the most effective protection is a willingness to experiment, Christensen advises.
One of the most damaging things deer do to trees is rub trunks with their antlers. Deer shed their antlers every year and then grow completely new ones. The regeneration takes the entire summer while the shedding takes two or three weeks as the velvet that supplies the antlers with nutrients disconnects. Deer help this process by rubbing their antlers against tree trunks. "They also do it to mark their territories for mating season," Christensen says. "And it takes the bark right off of a tree to the cambium layer."
This rubbing can do the most damage to small, young, flexible trees - the ones deer seem to like best in fall. For new plantings, Christensen recommends black, plastic guards to physically block deer from the tree trunks. They have UV protection to improve longevity and do not harm the tree when attached with zip ties.
When it comes to keeping deer from nibbling on your tree's leaves, Christensen recommends hanging several bars of soap from tree branches. Repellents, usually made up of predator urine, seem to work as well but need to be reapplied after rainstorms wash them away. "But given the smell, they have a tendency to repel people as well as deer," remarks Christensen.
And if you are considering installing a new garden or younger trees in an area with a higher deer population, Christensen advises installing a barrier such as nets or fencing before the trees are planted. "Doing it after they've found the food source means they are more likely to jump your new fence or find a way to enjoy another helping."
And if all else fails, consider man's best friend, Christensen adds. "If there's available food that is easier to get - meaning deer don't have to avoid a dog or leap a fence - then they'll usually take the easiest route."