Lilac FAQs

Guest post by Emira Mears

I saw a comment pop up on an old post of mine from last May about Lilacs that I thought I would pull out and do my best to address here. The comment, or rather question was about a healthy seeming lilac bush that doesn’t seem to be producing much in the way of blooms (or perhaps any). I did a bit of research into this as lilacs are one of my absolute favourites and I do worry a bit that the lack of hands on care that I give our lilac will result in a decline in the plants health. There have been (and continue to be) a lot of plants we inherited in this garden that I need to learn more about. Anyway.

From the reading and web searching I’ve done I can contribute the following info and a few more questions for any of you out there who have more knowledge or tricks up your sleeves:

  • Lilacs apparently don’t need heavy pruning but can do with a bit of thinning out. I know that my own bush sends off suckers and and new shoots a few feet away from the main bush as well as in the centre clump, pruning back some of these will apparently help the plant thrive as it is a heavy feeder or nutrient sucker so cutting back on some of the greedy shoots is a good idea. From what I’ve read I was a bit unclear as to when one should do this, so I’m not sure if it’s a Spring prior to blooming thing or a Summer post-blooming activity. Do chime in if you know. (And I should mention everything I have read has specifically pointed out a need to not over prune, so don’t go too nuts).
  • Cutting off finished blooms is apparently one way to encourage a healthy crop of flowers the next year. Now if you’re not getting any flowers that won’t help, but I do know that this is something I have not done at all really, but have now logged into my garden journal for this June/July to take care of.
  • Soil conditions: limey. Or so says the reading I’ve done. You can spread dolomite lime or other limey additives in November in my climate (zone 8ish/BC west coast).
  • lilac between the hedge and garageDividing or moving: Here’s where my big questions come in. I’m a bit worried about the location of my own lilac (between a healthy growing laurel hedge and a garage as seen in the photo there) and that lack of sunlight due to the physical constraints (it does face south so still gets lots of sun) will eventually cause it to suffer. If I wanted to take some of the offshoots and move them to a different spot in the yard, when would be the best time to do this? Or, say if I wanted to move the whole bush?

If any of you have any other tips for healthy lilac blooms do pass them on. I know I’m keen to do all I can to keep those gorgeous beauties bountiful each May.


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7 thoughts on “Lilac FAQs

  1. I grew up in the midwest where landscapes were hedged in fragrant sping blooming lilacs.
    A few tips I have learned over the years:
    Lilacs do best in full sun. Although I can’t remember seeing anyone pruning the hedges, my mature lilacs respond to pruning out some of the old canes. New buds begin forming after the Spring bloom. Start pruning out a few of the very mature branches by cutting them out at the base of the shrub. Space the cuts so that you keep the shrub’s natural shape. Pruners have a 1/3 rule and it helps in this case to allow new shoots to begin filling in before the next thining. Lilacs aare seceptible to powdery mildew. I believe this thining process helps with better air circulation and promotes young healthy growth.

  2. We have some lovely neighborhood lilacs that were
    forced to be pruned due to the city installing giganitic no parking signs every 4 ft or so in the bushes- I’m hoping that this will resulting in heavier blooms taking over this year-pics in my flickr-
    I’m going to track their progess further with more pics.

    PS- I’m with Julaine- they really need full sun, but for some reason people always want to put them in alleyways beside garages..not sure about moving them-think that could be risky- can you prune back the laurel a bit & allow it to share the space?

  3. If your shrub faces south, then it’s probably getting a good dose of sun. It might just be a little leggy on the bottom if there’s shade down there. The only thing I would be concerned about in that location is that, being so close to the laurel hedge and not much soil to spread out in, the lilac’s roots will be competing with the laurel roots for nutrients and water. I have an idea of which plant might win that fight.
    Also, the best time to transplant any shrubs is the fall. This gives the roots a chance to establish themselves before spring, when the plant’s energy is concentrated on new shoots and flowers.

  4. I was hoping to find out some information on growing a lilac bush in a container. I live in Salt Lake City, and live in an apartment. I love lilac’s yet I was hoping this would be something I could put in a container. Do you have any helpful ideas or information on this type of gardening.

  5. I have a very mature lilac bush, (30′) it has become very woody with little blooms. My home is 100+ so I am sure the bush is close to that age. How can I revive her?

  6. help! my one year old lilac bush only produced one blossom this year and no buds! is it a dud? it’s in full sun and has good soil. there are lots of heathy leaves just no buds. any ides as to how we can fix this?


  7. My lilacs bloomed nicely this spring and now i have the remains on the branches. Will they bloom again? Should I cut off the old blooms? These plants are 50+ yrs old.

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