Not wilted. Curled.

Any chance -- even though it may be very slim -- of weed killer used anywhere in the vicinity? By you? a garden helper? a neighbor?

Actually you're on to something. I've been using some Round Up on some weeds around the garden. It's not supposed to hurt desirable plants but could that be it?
Thank you!

RoundUp will harm any growing plant that it comes into contact with. It can also be absorbed through cracks or lenticels in the bark, though people don't want to hear that.

If you read the label on your herbicide, you'll find warnings about getting it anywhere near valuble plants.

But, the weeds I sprayed are on the ground and I just sprayed the weeds. I was careful with the Round Up and there wasn't any wind....

What do you do about weeds that are in the middle of your perennials, shrubs?

Thank you! Caren

Dig up the weeds by hand and then apply a mulch to prevent further weeds.

Herbicides and all other pesticides often go off-site via the turbulence of the spray..

Thank you for everyone's advice. You don't think there is anything else it could be?

Thanks again,
Caren

Lilacs are particularly sensitive to any plant poison and the can often absorb any applied to the soil through the roots. Even though these glyphosate products are only supposed to work if absorbed by the plants leaves I have seen just what you have too many times to not suspect that is what your problem is.

Wow! I'm so glad I know this now. Thank you so much for your help I really appreciate it!
Caren