We've been keeping busy at the Plant Clinic. Here's an overview of common issues we've seen in the first 4 months of 2017:
123 plant samples submitted for diagnosis or ID with 250 diagnoses (due to samples often containing several problems). We usually see a lot of evergreen samples in spring, and this year has been no different.
Boxwood (32 samples) – Abiotic damage (19, many of them are freeze/frost injury); Volutella blight (16); boxwood leafminer (9); boxwood psyllid (8)
Spruce (29 samples) – Abiotic damage (12, mostly Colorado spruce); Stigmina needle cast (16, mostly Colorado spruce); Rhizosphaera needle cast (15, mostly Colorado spruce); Cytospora canker (6, mostly Colorado spruce); Sudden Needle Drop (SNEED) (3, on Norway, black hills, and Colorado spruce); spruce spidermite (3)
Pine (15 samples) – Dothistroma needle blight (5, mostly Austrian pine); Diplodia tip blight (4); lots of reports of white pine problems, probably abiotic
Arborvitae (6 samples) – Phyllosticta tip blight (4)
Lots of stress issues, mostly tied to the extremely wet and suddenly chilly weather – oedema on yew, various cankers (cytospora on hemlock) and various scale insect issues