Lilac problems

Watch Reply
More
Mark unread Print Skip to new
Teresa_IL Bolingbrook, IL(Zone 5a) May 09, 2006

2 years ago, in spring, I planted a common lilac, about 1 ft tall, in full sun. It bloomed profusely both that year and last year. Now its 4 feet tall, bushy and full, but no flowers.

Next to it, last year I planted a tinkerbell lilac, while it was blooming, about 2 feet tall. This year it is 3 feet tall, and blooming great, but with several dead branches and very few leaves.

I'm kind of at a loss for why the first lilac wouldn't have flowers, when the younger one would (same soil, light, water conditions) I didn't prune it at all last year.

And, I am not really sure what to do about lilac #2 either. Should I prune it way back, so it grows in bushy? Or just cut off the blooms and dead stuff? Any other suggestions?

And I thought lilacs were supposed to be easy...

Thumbnail by Teresa_IL
Post #2263450
Quote
PrairieGirlZ5 Thornton, IL May 09, 2006

If you do cut off the blooms, crush the stems, they'll take up water in the vase better, l& ast longer. By all means, cut off the dead stuff. After that, I don't know.

Post #2263748
Quote
Ivy1 Mystic, CT(Zone 6b) May 10, 2006

Are the dead branches all on one side? Or are they scattered about? Is the dead wood at the tips of the branches?

Post #2265432
Quote
Teresa_IL Bolingbrook, IL(Zone 5a) May 10, 2006

They are scattered about... it seemed almost every branch had some smaller dead branches, and there were a couple of big ones as well

Post #2265494
Quote
StarhillForest Illinois, IL(Zone 5b) May 10, 2006

One possibility might be borers. Google for Podesia syringae and see what it says. We trap for borers here and spray our old historic lilac as soon as we start seeing the males in the pheromone traps. Usually this spraying is done in alternate years, which seems to give us sufficient control. Too bad we can't trap the darned females -- that would be a lot better than spraying witches' brew out there to kill them.

Guy S.

Post #2265548
Quote
Ivy1 Mystic, CT(Zone 6b) May 10, 2006

I had some dieback this year, mostly on the tips, and especially where seed pods were forming.

How close is it to the other bush, and to other plants?

I am going to try pruning back a third this year for shape to see what happens.

Post #2265554
Quote
Ivy1 Mystic, CT(Zone 6b) May 10, 2006

What do you spray with?

Post #2265558
Quote
StarhillForest Illinois, IL(Zone 5b) May 10, 2006

Quoting:
What do you spray with?

You don't wanna know. It's a deadly blend of things that aren't even legal to buy anymore, and certainly not suitable for anyone who is not well versed in toxic substance use. I use it carefully and in small quantities, with all the necessary precautions, rather than sending the ingredients to a landfill, because the use was still on the labels when I bought them. And I use it only on very special/valuable plants.

Go to your local garden center and ask for a spray that will handle ash-lilac borer. But first use a pheromone trap or dissect and examine an affected stem for borer galleries to see if that's even the problem. Probably too late to treat this year, but set the trap out next April and watch for wasp-like male borers (clearwing moths) to appear in it starting around May 1 or so. Spray as soon as they appear, but only IF they appear.

If you have no borers, do not risk the collateral damage to other organisms by spraying anyway. And if you have a minor problem that can be addressed by merely cutting out and burning the older, infested wood, do that instead. We can't do that with our 1875-era lilac because it's being grown in tree form.

Guy S.

Post #2265708
Quote
escambiaguy Atmore, AL(Zone 8b) May 10, 2006

Wouldn't Imidicloprid (Bayer)work as a soil drench? It is advertised for borers.

Post #2266241
Quote
StarhillForest Illinois, IL(Zone 5b) May 11, 2006

I don't think it's labelled for clearwing moths and other Lepidoptera, just Coleoptera types like birch borer and EAB.

Guy S.

Post #2267300
Quote

Post a Reply to this Thread

Please or sign up to post.
Back to Forum Homepage

More Trees, Shrubs and Conifers Threads

Go to all Trees, Shrubs and Conifers threads
BACK TO TOP