Taking Care of Your Oak Trees: When and How to Trim

Date August 26, 2021

Author TreeNewal Staff

If you’ve been heeding the warnings not to trim or prune Oak trees from February through June, then you might have some pretty scraggly-looking Oak trees on your property right about now. The good news is that we’ve made it past the peak of Oak Wilt season. Although it’s now generally considered safe to trim your Oak trees, you still need to be careful and make sure you’re using the proper Oak tree trimming and pruning techniques. Even in the summer, you need to be wary of making your trees vulnerable to Texas Oak Wilt. Here’s what you need to know about Oak Wilt and protecting your Oak trees of Texas.

What is Oak Wilt?

Oak Wilt is a vascular wilt pathogen that attacks Oak trees. It’s caused by the fungus Bretziella fagacearum, and once the fungus infects a tree, it invades and cripples the tree’s water-conducting systems, killing the tree in a matter of weeks. Oak Wilt is devastating our Oak trees in Texas, making it one of the biggest threats to our Texas trees. It is in more than 76 counties and nearly every city in Central Texas, including our own neighborhoods in Dallas-Fort Worth. It most commonly affects Red Oak and Lives Oak trees in our area, but it can infect any Oaktree, regardless of the age or health of the tree. Red Oaks, in particular, never survive an Oak Wilt attack, and they usually die within four to six weeks after showing symptoms. Infected Live Oaks usually live a little longer than Red Oaks, but they also have almost no chance of survival. A certified arborist might be able to prolong the life of a White Oak tree with an Oak Wilt treatment, but most will never fully recover. Oak Wilt prevention is the best method for managing this deadly tree disease.

What’s the big deal about Oaktree pruning?

Oak Wilt can spread in two ways. One way is by Nitidulid Beetles, which are attracted to the sweet-smelling fungal spores that Oak Wilt produces under the bark of infected Red Oak trees. They spread the disease long distances by carrying the spores to open wounds on uninfected oak trees. Oak Wilt can spread through root-to-root contact, which makes nearby Oak trees especially susceptible to infection. Using the proper methods when trimming your Oak Trees is one of the most important things you can do to avoid the spread of Oak Wilt. Whenever possible, you should avoid pruning Oak trees from February through June in North Texas because this is when fungal mats are actively producing spores, and it’s also when the Nitidulid beetles are most active. Plant sap that forms on the surface of cuts and wounds attracts the sap-feeding beetles. While they’re feeding, the spores attach to the beetles’ bodies, which they then carry to healthy trees. By not trimming Oak trees during this time, you can help prevent attracting these beetles to your trees.

Tips for properly pruning and trimming your Oak trees

In general, tree trimming and pruning are some of those tree health care tasks that are best left up to professionals. Using improper pruning techniques is one of the most damaging things you can do to your tree. Not only that, it can be very dangerous. A professional tree care company will have the experience and the tools needed to do the job correctly, safely, and efficiently. In the case of Oak trees in North Texas, working with a certified arborist tree service for all your pruning and trimming needs is especially important. Even in the summer, Oak trees need to be pruned very carefully to avoid making them vulnerable to Oak Wilt, and the cut should be protected with wound paint. However, if you do decide to prune your Oak trees yourself, here are some tips for how to do it properly:

  • Use the three-cut method. Starting about 10-12 inches away from the tree, make an undercut on the branch. Then, moving an inch or two further down the branch, cut from the top of the branch all the way through. We do this to avoid tearing when the branch’s weight pulls the branch downward during the cut. Then make the final cut closer to the tree.
  • When making the last cut, avoid the “flush cut,” when a branch is removed from a tree as close to the tree as possible, making it flush with the trunk or main branch. This cut is generally oval-shaped. Collar cuts tend to be more circular. The flush cut used to be standard pruning practice, but we now realize this method can lead to slow, uneven healing, making trees vulnerable to pests and diseases like Oak Wilt. Instead of the flush cut, use the collar cut, which leaves the swollen part of the tree, where the branch and trunk meet, intact.
  • No matter the time of year, always paint the wound after trimming your Oak trees. Using wound paint is unnecessary and can even be harmful on most trees, but Oak trees are the exception. Using wound paint with an asphalt or latex base creates a protective barrier between the fresh cut and the sap-feeding insects. To apply, paint in a thin layer immediately after the wound is created. Wound paint should be applied no matter the size of the cut.
  • If you suspect your tree is infected with Oak Wilt, you should call a certified arborist so that trained professionals can remove the tree from your property. There’s a lot involved in making sure an Oak tree infected with Oak Wilt doesn’t spread the disease to other Oak trees in the area.


TreeNewal can handle all your Oak tree’s health care needs.

If you have questions about pruning your Oak trees or think your tree might be sick or dying from Oak Wilt, work with a certified arborist tree service company like TreeNewal with ISA Certified Arborists with ISA official Oak Wilt Qualifications. Our arborists have undergone specialized training in the identification, prevention, and treatment of Oak Wilt disease. TreeNewal has the tools and knowledge to perform safe branch and tree removal techniques, including disposing of diseased materials and performing other preventative measures to stop further spread of Oak Wilt. TreeNewal offers a full range of expert tree care services, including professional trimming and pruning for Oak trees any time of the year and even emergency pruning during Oak Wilt season. We care deeply about protecting your trees from disease, pests, fungus, and any other ailments. For more information about our tree care services, go to our website at treenewal.com. To set up an appointment, call us at tel:(817) 592-6846.

To learn more about Taking Care of Your Oak Trees: When and How to Trim, call our Argyle and Southlake-based teams

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