Question
I have two (old) lilac bushes and a catalpa tree in my front and back yard in the Montreal, Canada area.
This year I got almost no lilacs after a glorious showing  last year. Instead, all the leaves on both bushes are curled and shriveled, mostly curled under. As well, the (usually) gigantic leaves on the catalpa tree came in the same way. (My ash tree is fine.)
They are all situated on lawns that are treated by a lawn service, but no pesticides are used.
Is there a treatment?
Thanks,
Carol Tynan

Answer
Check the undersides of the leaves for small insects such as spider mites or aphids and scale insects.  If you find any evidence of the cause of the curling, you will have to treat with an insecticide.  If you find no bugs and the weather has recently gotten real hot and/or dry, then it could be just the heat causiang the curling.  Please respond back with your observations and we can go from there.  Thanks.