Is this verticillium wilt on my magnolia?

Question

I am fairly certain that the magnolia tree we planted a few months ago has a fungal infection of some sort. I’m terrified that it is verticillium wilt. It has not rained here in ages and has been abnormally hot. I checked the stem vascular tissue and no brown streaks. But the leaves and bark worry me. I’ve sprayed with tebuconazole but it doesn’t seem to be helping. Any help would be appreciated.

Answer 1

It appears to be fungal/bacterial, but this is not Verticillium.

It sounds like the tree was planted a little too late in the year. It is best to plant these in early Spring, since they are quite cold tolerant, but won’t take well to the soil in the heat. Pair this with lots of water in attempt to compensate for hot weather and you have the perfect recipe for infection.

It sounds like you are already treating the best that you can for the upper portions of the tree. Cooler weather will take care of the rest. You can help it out by removing any heavily infected growth or anything that is completely dead, but don’t butcher it up too badly at this point.

I would also suggest WETTABLE SULFUR and DOLOMITIC LIME together in the soil. Do this once per year around the tree where its roots extend to. This will help keep infections at bay, and treat existing ones.

This article will help you with the care of Magnolias: https://www.gardeningknowhow.com/ornamental/trees/magnolia/magnolia-tree-care.htm