You can find numerous varieties of oak trees in California, such as the California live oak, Englemann oak, and the Oregon white oak. If you have oak trees in your yard, you need to be aware of some of the most common oak diseases that can impact your oak trees and how to protect your oak trees from damage.
1. Oak Leaf Blister Disease
The fungus Taphrina caerulescens spreads oak leaf blister disease. The fungus lands on oak trees during the winter time, which leads to infected leaves as they emerge and develop in the spring.
Oak leaf blister is easy to see once a tree is infected. The leaves on the tree have visible deformities on them. Spots develop on the leaves, which start out as green spots, then turn white as the fungus grows, and later become brown spots.
The oak leaves stay on the tree and don't fall off early. Oak leaf blisters are visually unappealing, but they generally do not compromise the overall growth of mature trees. The disease can be more damaging for younger trees.
Oak leaf blister can be treated with a fungicide application in the early spring before the buds open and the leaves start growing. Oak leaf blister disease can also be managed by raking up and disposing of all infected leaves every fall.
2. Hypoxylon Canker Disease
Hypoxylon canker is a disease caused by the fungi Hypoxylon atropunctatum that infects oaks and other shade trees. Although, the fungi Hypoxylon atropunctatum is not a really strong fungi. Plenty of healthy oak trees have the fungi Hypoxylon atropunctatum on them, but healthy trees can fight off the cankers using their own natural defenses.
Hypoxylon atropunctatum is dangerous when it lands on stressed out or unhealthy trees. The fungi settle on the bark and create a brown area on the tree. This spot turns silver as the fungi grows, which creates a hard canker on the tree. These cankers generally first grow on vulnerable branches. Pruning can stop the spread of the disease when the cankers are first detected on branches and limbs.
When cankers develop on the trunk of the tree, the health of the tree is in trouble. The cankers damage the bark and disrupt the transportation of nutrients, which can kill your oak trees. At that point, the tree needs to be cut down.
The best way to keep your oak trees from being killed by Hypoxylon canker disease is by keeping your oak trees in good health.
3. Oak Wilt Disease
Oak wilt is an exotic disease that oaks do not have a lot of natural defenses against. Oak wilt is fatal and can be devastating; it can wipe out or greatly reduce the oak population in areas it hits. Oak wilt is a fast-moving disease. It can kill and wipe out an oak tree in a matter of months.
The fungus Ceratocystis fagacearum spreads the oak wilt disease. Oak wilt disease is spread when the roots of an infected tree comes into contact with another oak tree. Oak wilt disease is also spread by boring beetles, who often carry the fungus with them.
The best way to protect your trees from contracting oak wilt is to prune your trees during the winter so the wounds have time to heal before beetles can take advantage of the wounds left behind by pruning. You can also paint over all wounds with latex paint to protect them from beetles.
Oak wilt often first shows up in the leaves, with leaves turning brown and wilting off the tree far earlier than they should. Then, whole sections of the tree will start dying off.
With oak wilt, treatment is often about preventing the spread of the disease. The first tree spotted with oak wilt is often a causality. But you must break up the connecting oak tree roots to stop the further spread of oak wilt disease.
The best way to protect against diseases that can harm your oak trees is by keeping your trees healthy to begin with. At Anderson Tree Company, we can help you take care of all of your trees.