A potentially fatal disease called Oak Wilt (Ceratocystis fagacearum) is beginning to spread more rapidly this time of year, and pruning Oaks during the growing season could expose them to infection.  Oak trees are common to our north eastern region and many people may want to act on the opportunity of warm weather now that it’s spring season to start their pruning. But with oak trees, it’s important to wait for the colder months to take action with pruning. Diseases and pests tend to become activated in the warm months of late spring to early fall. Oak wilt is one disease that is common for oak trees in these months and is the reason we’re suggesting to wait before pruning.

What exactly is Oak Wilt?

Oak wilt is a fungal vascular disease. It creates mats of fungi between the bark and sapwood layers of the tree, which then attract insects and beetles. The insects can carry fungal spores from an infected oak to an open wound on healthy oak.  If not treated it can even cause rapid decline and eventually death. It also is spread through root grafts or by nitidulid. Root grafting commonly occurs when trees of the same species are growing within up to 100 feet of one another. It’s especially hard to treat as oak trees share root systems and the fungus can spread from tree to tree below the surface.

How does pruning affect Oak Wilt?

Pruning, though an important part of tree care and safety, causes topical wounds to the trees. Fresh pruning wounds attract insects with exposed soft or wet tree tissue. Since most insects are only active during the growing season, they can transfer mold and fungal spores from an infected tree to a healthy tree.  Oak wilt can take over while the tree is still sealing the wound. Pruning trees in the winter months allows for those wounds to dry and harden before insects become active. When trees are pruned in the summer, especially when oak wilt is detected, the tree doesn’t have the time to seal the wounds.

When is a good time of the year for pruning?

Oak tree pruning is best completed in the late fall or winter. We recommend saving your oak tree pruning for November through March. Our teams and crews are available now to do a level 1 assessment to check on the health of your oak trees. If oak wilt is a problem, you’ll want to have it treated right away since the disease can be fatal if not treated immediately.

Call Cutting Edge Tree Professionals today 814-201-9757, or use our contact page. We’ll get you on the schedule for your oak trees or other tree and plant care concerns.

Sources:

https://www.rainbowtreecare.com/tree-health/disease/causes-oak-wilt/

https://arborjet.com/problems_solutions/oak-wilt/