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If you’re thinking of hiring a tree pruning service to trim your oak trees, make sure that you understand the right—and the wrong—time to prune oaks.

According to the Texas Forest Service, pruning oak trees between February and the end of June could cause significant problems. This post will help you better understand the seasons oak trees go through as well as proper pruning to help prevent the highly destructive oak wilt disease.

Oak Tree Seasons

To help stop the spread of oak wilt, it’s useful to know a little bit about the seasons that oak trees go through. They react differently to things like disease or insect infestation depending on the time of the year and what part of their growth cycle they’re in.

Right now, during the winter months, deciduous trees like oaks are dormant. Their limbs are bare and their sap has settled primarily down into their root system. Having no leaves is actually a benefit during this time because they are able to shed ice and snow much more easily, which makes damage from broken limbs much less likely. In many trees, you can spot small buds on the ends of branches that are waiting to open in the spring.

When temperatures start to rise during March, April, and May, oak trees begin waking up and sending nutrients out to the new growth. During this season, they are putting a lot of energy into producing new leaves, so they aren’t as quick to heal from disease or physical damage.

By summertime, oak trees are full of leaves that are capturing as much energy from the sun as possible. Chlorophyll helps the tree produce the sugar it needs to survive.

Then, in the Fall, as things begin to cool down again, they stop producing chlorophyll in anticipation of going dormant again soon. It’s that absence of chlorophyll–the green disappears–that reveals the red, orange, and yellow colors of the leaves underneath.

Oak Wilt Season

Oaks are typically divided into two categories: white oaks and red oaks. We have both kinds growing in our part of North Texas, and they both are susceptible to oak wilt.

Oak wilt is an aggressive tree disease that has reached epidemic proportions in Texas. In the Dallas-Fort Worth area that we serve, we see it all the time. This map from TexasOakWilt.org shows the Texas counties with confirmed cases as of 2019. No doubt, it has only spread further since then.

Oak wilt is caused by a fungus that gets into the water carrying system of the trees. Once there, it disables that system and ultimately kills the tree.

The fungus is delivered by a beetle that seeks out oak tree sap. When it feeds on an infected tree then travels to another tree, it passes the fungus along. The fungus can also spread quickly underground through the interconnected root systems of oaks like Live Oak, White Shin, Lacey, and Chinquapin.

Because spring is the time when these beetles are most active, this is the time when oak wilt is most commonly spread. That’s why it is not recommended to do any pruning on oak trees between February 1 and June 15.

Pruning Live Oak Trees

In the cold winter months or the hot summer months when the trees are less vulnerable, it is much safer to prune your oak trees. Ideally, you want to prune dead branches or remove any unwanted limbs in the winter just before springtime. As the tree is preparing to put out new growth, it can repair fresh wounds much more easily in the months before insects are active.

We cover the best way to prune trees in another article titled “3 Important Things to Know About Tree Maintenance Services.” You can check that out for more details. But a good basic pruning technique looks like this:

1. Avoid trimming and pruning unless absolutely necessary. Any cut you make creates a fresh wound that can become an open doorway for infection.
2. Use clean tools. Just like oak wilt spreads by beetles from tree to tree, it can travel on dirty pruners and saws. Using a basic Lysol disinfectant between pruning jobs makes a big difference.
3. Make clean cuts. Using proper techniques will keep limbs from ripping bark away when they separate. By making the wound as small as possible, you create less opportunity for infection.

a. On larger branches, start with an upward cut that      doesn’t go all the way through.

b. Make a complete second downward cut a little closer to the branch from that spot that will separate the limb from the tree.

c. Finish by removing the “stump” of the limb by making a clean cut close to the tree, just outside the point where the limb flares out as it meets the trunk. The tree will then be able to close the gap and heal itself. (It is not necessary–it could be harmful–to apply any sort of wound dressing.)

Trust Your Oaks to a Qualified Tree Pruning Service

For more information on oak wilt, check out this informative article from Texas A&M.

To help control the spread of oak wilt in North Texas, trust your oak trees to the care of a certified arborist with an experienced tree pruning service. LH Services regularly provides professional tree services in Dallas, Fort Worth, and surrounding areas.

We understand how valuable your trees are, and we’ve got over 20 years of experience in keeping them looking great. Schedule a free estimate to see what we can do for you!

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