What a wonderful day. It’s not often that we get to enjoy temperatures in the 50’s and 60’s in mid-April. Like our trees, plants, and wildlife, we are happy to have these life-giving rain showers. It’s a great time to catch up on my research, report writing, and a newsletter to you.
However, now’s not the time to perform widespread pruning of our live oak and red oak trees. According to texasoakwilt.org, “All wounding of oaks (including pruning) should be avoided from February through June.”
4 out of 5 of these leaves are likely symptomatic for oak wilt. Can you tell which ones are?
Over the last five or six months, I’ve seen more cases of active oak wilt than at any other point in my career. I have seen a multitude of new infection sites throughout Austin and Central Texas. Sadly, I’m also seeing a considerable amount of routine pruning to oaks this spring during the high risk season. This puts not only those trees being pruned, but other trees in the surrounding neighborhood, at risk for oak wilt as well. Why is pruning oak trees in the springtime problematic?
One of the primary pathways for oak wilt transmission is through nitidulid beetles, which carry spores of the causal fungus, Bretziella fagacearum, from infected trees to fresh wounds on healthy oaks. The beetles can migrate several miles and are attracted to open wounds on oak trees. Wounds that are 72 hours old or less are vulnerable to oak wilt transmission.
Why is this problematic? According to texasoakwilt.org, “Most live oaks defoliate and die within 3 to 6 months following initial appearance of symptoms. Red oaks never survive oak wilt and often die within 4 to 6 weeks following the initial appearance of symptoms.”
Oak wilt isn’t just spread by the beetles, infected oaks spread the oak wilt fungus through common grafted roots at an average rate of 75 feet per year. It is an unfortunate fact, that you can follow the oak wilt prevention protocol, but your trees can be vulnerable if your neighbor doesn’t. It takes care on the part of all residents of a neighborhood to prevent the spread of oak wilt.
Here is your call to action. Unless people or property are at risk, do not wound your oaks from February through June. Talk with your neighbors about oak wilt prevention. I am also available as a speaker to discuss oak wilt with your HOA, garden club, master gardener group etc..
Do enjoy this fabulous spring weather! Now’s not the time to prune your oaks.
Best regards friends,
