Could this be a virus on the leaves? I have a kalmia latifolia ostbo red that is currently in bloom... The first time in 5 years...very beautiful. It is small and in a pot standing about 3 feet tall. It lives in North Vancouver on a balcony, by itself, but in close proximity are two lovely old magnolia trees, roses, and rhodos. Three persons at a gardening centre were not sure...but thought that a virus was the best bet...and said that it was impossible to get rid of and that it was contagious to other plants and that I should get rid of it. The infected leaves inhabit about 45% of the plant. I'd love to save it - it is so lovely. What do you "people in the know" think? Are they right? This is my first post so I apologize in advance if I have not posted in the correct place. I look forward to hearing from y'all. joZ
This is undoubtedly necrotic ringspot virus. See this link. This disease evidently first appeared in Oregon in the mid 1970s and is now widespread in the Pacific Northwest. In my experience, it is not a particularly virulent disease, but plants should probably be destroyed (as is recommended in the linked Rhododendron Fact Sheet). This is because rhododendrons and kalmias are similarly affected and virus transmission is typically facilitated by vegetative propagation, and most likely, also by pruning. Disinfecting your secateurs may be harder than you might imagine. You can always get another plant, as this cultivar is fairly common, but I would check for symptoms where you shop and let the retailer know if her/his plants are infected. I hope this helps.
Thank you for your reply. I tried finding similar pictures to my kalmia's problem but I failed. It was helpful to get the link you sent. In waiting for a reply, I went to another Gardening Shop for a "second opinion" and this person identified it as a virus, did not name it however, but did say it was not necessary to throw away the plant nor was it "contagious." You have more clearly defined the problem and now I know what I must do. You have been a great help and I am so glad I found this forum. Sincerely, joZ
I've posted this same comment on a different, much older thread, but will try again: I'd LOVE to have an Ostbo Red Kalmia. Where would I find one? Janet
Maybe phone around a little, Garden Works in Burnaby, Cedar Rim in Langley, Cannors in Abbotsford. Should be able to find 2-3 gal. blooming size named cultivars easily. Not uncommon , but likely a better choice in the spring.