Why do my beautiful lilac trees never bloom?

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I have two lilac trees that come spring, have beautiful green foliage. But when it's time for the ends to bloom, all the flower buds shrivel up and never bloom. I have tried lime, different fertilizers, but no luck. I have not taken a soil sample to the local extension office.
  8 answers
  • Janet Pizaro Janet Pizaro on Apr 30, 2017
    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?

  • Lisa Aho Ferguson Lisa Aho Ferguson on Apr 30, 2017
    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.

  • Snoce Snoce on May 01, 2017
    Mine only bloom on new growth branches. When do you prune them?

  • Elga Ray Elga Ray on May 01, 2017
    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?

  • Pam Vaughan Pam Vaughan on May 01, 2017
    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 !! :)

  • Maryl630 Maryl630 on May 01, 2017
    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.

  • Janet cross Janet cross on May 02, 2017
    I have also read to put bone meal around them every 3-4 months... I am trying that this year

  • Michelle Leslie Michelle Leslie on Jun 06, 2020

    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