If they already have formed next years buds, pruning now will result in no or few blooms next year. Seems kinda fast for them to have done that if they just quit blooming.

Yes, you can cut off the leaves with the powdery mildew. I read about an interesting cure for Powdery mildew. Spray with one part milk mixed with 9 parts water. Don't know if it works but am going to try it on my dozen June Berry (AKA Saskatoon Berry) bushes. They are solid mildew.
Jan

Only one of my two lilacs even bloomed this year, and the one that bloomed didn't have very many flowers on it. They lasted maybe a week. I pruned them right away. While i was watering this morning, i noticed buds too. Hope that means it will bloom more next year. Not sure what happened to the other one. It came out from under the snow with leaf buds but never flowered. Shrug.

Marcia, Your lilacs that just put on a few flowers this year will likely have lots next year.

I planted lilacs down both sides of my property a few years ago....I just cut them back after planting, then the next year...they grew nicely...I cut back again to shape a little of some of them....at the expense of the flower buds of course. Last year they had a few flowers here and there. This year there were lots.

I don't even bother to take the spent flowers off.....I'm to lazy for that LOL.

So yes mcav0y , if you clip them back...you will lose next years flowers.

Sierra

thanks for the tips! I think I will prune the areas prone to powdery mildew and shape it a bit. I won't go too drastic this year so that I will have blooms next year.

But next year, look out!!! Giraffe-shaped lilac bush, here I come!!!

Is there a happy medium between lilac pruning and flowering? I like my hedges small and neat because my yard isn't really big, but I hardly ever get any lilac flowers because I'm always cutting them back.

LOL about the giraffes. When I was in Mexico last winter, on the road between Cancun and Playa del Carmen there is what seemed like half a mile of box hedges (I think, I didn't get out to check the species) all clipped into animals. I was in love with them. There were dolphins, giraffes, roosters, baskets, horses, frogs, that I remember. So cute! Not that I want them in my garden but they were fun to look at on the road.

Don't want to hijack, but, my Lilac bushes (5 of them) are about 5 years old and haven't bloomed yet, (one or two very small bunches). If there are borers, would that prevent flowering, or has anyone else had this problem with no blooms?

I wonder if the snow load breaking branches (since earlier in this thread someone said that pruning prevents new flowers) could be the cause...?

No sign of mildew or other disease or pests...

Any help would be helpful... :)

-S

Yes, I have the same problem. Two healthy, getting-large lilacs, about five years old, never have bloomed. They seem to get enough sun, although it's not full sun, but at least as much as other I have that DO bloom in another part of the yard. Would cutting them back help?