If you have an orchard where individual trees are yellowing, have thin canopies with small leaves, or lack of new growth, gopher damage is a possible cause. On some rootstocks, root rot or oak root fungus could also be possibilities and this should be checked out. If it’s gophers, they can be the cause of significant ongoing tree losses. Gophers chew off roots and can chew off bark all the way around the trunk at the crown right down to the wood. If you dig around a sick tree and find the bark missing 2 or 3 inches below ground level, you can bet that a gopher is the culprit most of the time. If the orchard is weedy around the tree trunks, providing cover and protection, meadow voles can chew off bark at ground level girdling trees and causing a similar decline.
Gophers are active all year and this is still a good time to reduce their population. It’s easy to see new signs of their activity when weeds are being controlled for harvest and new fresh mounds are evident. If you carry a poison dispensing probe with you and use it each time you see fresh mounds, you can sharply reduce the gopher problem in your orchard.
Gophers eat year around. If you do a good job of weed control in your orchard and you have active gopher mounds you can be certain the gopher will be feeding on your trees as harvest approaches. Gophers can damage any age tree. The easiest trees for a gopher to kill are first through fourth leaf trees because they can girdle them quickly. I’ve also seen 10 year old trees killed by gophers.
The longer gophers work on trees, the weaker the trees become. Oftentimes the damage doesn’t become apparent until the year after the injury has occurred since it may take awhile for the root system to starve and decline, especially on older trees. Remember, leaves manufacture sugars that are translocated down through the phloem to feed the root system.
When gophers chew off the bark the phloem pipeline to the roots is missing and the root system gradually starves.
If the gopher doesn’t kill the tree and it’s only partially girdled, it can be permanently weakened with the damaged roots or crown becoming avenues of entry for crown gall and wood rots. Wood rots weaken the structural strength of roots and the crown and contribute to tree losses in windstorms.
Gophers are a serious problem but they can be stopped. Don’t pass up this opportunity to control gophers in your orchard by using a probe now.