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by Jenelle
(Newfoundland, Canada)

My mother lives on a small island in rural Newfoundland, on the coast, where we’ve been growing a lilac and snowball tree for many years, probably close to 20 years.

They have been healthy up to last year, but they have been exhibiting a strange leaf curling, and blackened leaves. We would like to know how to handle it.



Hi Jenelle, there are a couple of things that this could be as it’s on both of the trees at the same time.

If it’s on new growth, and it’s on both of them, this could be frost damage. Even a light frost can cause this; the good news is that they can survive and put out new leaves really quickly.

If it’s happening on older growth, last year maybe? Then this could be black sooty mold, which is caused by either aphids or other pests, and the mold (which is harmless but unsightly) grows on the honeydew (a polite term for aphid excretions).

Aphid damage can also cause curling of the leaves if there are huge populations of them.

A soapy spray, a couple of times in 24 hours will generally get rid of most of the aphids; if there are ants around, get rid of those too, because they ‘farm’ the aphids, and move them around just like a herd of cows.

If it does it again this year, take some pictures and send them; without seeing close up what’s going on it’s hard to give you any advice.

Hope that helps, sorry I can’t help more without pictures of the damage.

Best of luck,