Sad, Deformed New Growth on Monterrey Oak - Ask Extension
Howdy,
After the rains in August we were excited to see new growth on our Mexican White Oak. But after the initial leaf formations sprouted many of t...
Knowledgebase
Sad, Deformed New Growth on Monterrey Oak #361405
Asked September 10, 2016, 2:07 PM EDT
Howdy,
After the rains in August we were excited to see new growth on our Mexican White Oak. But after the initial leaf formations sprouted many of them turned crumply and gnarled. The new leaves that developed fully began to show yellow spots. The tree did show significant growth in a relatively short period, with many of the new leaf stalks extending over a foot within a month. But the gnarled leaves were a bummer because the tree had always been so healthy. We've had it for just under two years.
Thanks for your help!
Dave, Austin, TX
Travis County Texas
Expert Response
Hi,
Welcome to our incredibly odd summer! The heavy rains in May and then again in August have hit a lot of plants with fungal diseases. In addition to that, we've had problems with thrips and other sucking insects. It's a perfect storm that is causing your oak to not look it's best.
You can opt to treat the tree but it is so late in the growing season you might consider skipping it. The tree probably won't put on new growth between now and leaf drop so you'd be wasting your money.
Best thing to do is bag all the leaves when they drop and dispose of them (not in your compost!) to help clear away reinfections/reinfestations. Next spring when new growth arrives, keep a close eye out and treat if you see the symptoms reappear. There are several great fungicides - even organic ones - that you can use to spray the tree. Thrips are hard to control but on oak trees they usually don't show up unless the tree is stressed out by something else. Again there are several solutions you can try. Here is a great overview by UC statewide IPM Program. http://ipm.ucanr.edu/PMG/PESTNOTES/pn7429.html
Welcome to our incredibly odd summer! The heavy rains in May and then again in August have hit a lot of plants with fungal diseases. In addition to that, we've had problems with thrips and other sucking insects. It's a perfect storm that is causing your oak to not look it's best.
You can opt to treat the tree but it is so late in the growing season you might consider skipping it. The tree probably won't put on new growth between now and leaf drop so you'd be wasting your money.
Best thing to do is bag all the leaves when they drop and dispose of them (not in your compost!) to help clear away reinfections/reinfestations. Next spring when new growth arrives, keep a close eye out and treat if you see the symptoms reappear. There are several great fungicides - even organic ones - that you can use to spray the tree. Thrips are hard to control but on oak trees they usually don't show up unless the tree is stressed out by something else. Again there are several solutions you can try. Here is a great overview by UC statewide IPM Program. http://ipm.ucanr.edu/PMG/PESTNOTES/pn7429.html
