I've noticed odd brown nodules on an otherwise healthy wisteria in full bloom. The nodules are covering the stem and pick off easily. Inside they are dry and powdery. Should I be worried about this? The wisteria grows well every year and is approx 16 years old.
Certified GKH Gardening Expert
It appears to be spores of some kind. Scale insects would leave a sticky residue.
Watch for that.
You could treat with Neem Oil.
Here are a couple of links.