Why do my beautiful lilac trees never bloom?

Where are they planted? Do they receive ample water?When have you fertilized? What kind of fertilizer was used?Were they pruned at any time?

It's been awhile since I fertilized, since it didn't make a difference. They are in full sun against my cedar fence. I also have a huge hydrangea bush on same line that did the same thing for 20 years. Now it has the most abundant blooms ever.

Mine only bloom on new growth branches. When do you prune them?

Have you tested your soil? They need good soil and fertilizer to bloom. Sometimes, trimming them back will help also. Do they get enough sun?

my best year yet! I have been growing mine for 5 years first 2.. nothing!! 3rd 2-3 blooms.. last year maybe 15 This year its loaded!! I did put some coffe grounds around the bottom because i thought it had a powdery effect to the leaves each fall.I just did it this spring tho. I thought I was buying bushes... these things ar20+ feet tall !! never fertilized or pruned yet! Beautiful !! :)

Do not trim lilacs after the Fourth of July. If you do, you will be removing next year's flower buds.

You may need to give it a severe root pruning. I did this to one lilac that hadn't bloomed for several years and it worked. It has bloomed every year since and that was at least twenty years ago.

I have also read to put bone meal around them every 3-4 months... I am trying that this year

Hi Lisa, you can prune it back. Just cut the branches you don't want, or those that are dead. They do like a good watering now and lots of sun. If your soil is on the dry side, you can amend it by adding Miracle-Gro® Garden Soil for Trees & Shrubs. In the spring, feed them with a good tree and shrub fertilizer. Here's a site that may add some more information: https://www.thespruce.com/lilac-bushes-growing-tips-2132722