We have what may be verticilium wilt on our acer palmatum. How can I verify the tree is indeed sick. Can I bring a limb sample in to have someone look at it to verify at the extension office Thank you for any info.
Multnomah County Oregon
Thank you for using Ask an Expert for help with your maples. Verticillium wilt is certainly a serious problem for Japanese maples, but it is not the only one.
These trees can suffer from too much water when planted near shrubs and perennials that receive frequent, regular watering affecting the tree’s root zone. Too-wet conditions cause damage to the roots which is expressed as wilting, early leaf drop, smaller or sparser leaf canopy.
Drought conditions (and we’ve had a couple of years of those) can cause similar symptoms—wilting leaves, yellowing, dropping leaves, and poor leaf cover. It can be difficult to tease out the real culprit affecting your tree.
I have attached two photos of branches with Verticillium wilt symptoms, for comparison with your branches. For one-on-one help, samples can be taken to the Multnomah County Master Gardener office in Montgomery Park at 2701 NW Vaughn St., Suite 450, in Portland. (10:00 am to 2:00 pm, Monday to Friday) or call 503-445-4608.
Good luck with your tree.