Old Overgrown Lilac? Cut It Way Back After Blooming!

How to make Old Lilac bloom again? Let me tell you what I did. It’s drastic, but it works.

I have a lilac that I planted here at my house soon after we moved in. It has been there for about 15+ years ( I don’t remember the specific year I planted it), but it was just a tiny twig from the nursery.  I am not sure of any variety but it is one of those regular or old-fashioned types which blooms fragrant purple blooms in late May.

My lilac bush has finished blooming this year and I am cutting it down! It has to be done. Let me explain what I am doing.

Image of fully blooming lilacs in pale purple

Where on the branch do lilacs bloom?

Lilacs bloom on newer growth, so the blooms will be on the new younger branches growing out from older trunks. Therefore as the bush gets older and older and puts out more and more new branches, since it blooms better  on those newer branches, gradually the blooms are all way up high and unreachable to gather for bouquets. 

image of lady gardener pruning lilacs

But that heavenly scent still floats in the air. Wonderful. But sometimes the older lilac get so overgrown and aged, they seem to stop blooming all together. Now that’s a sad thing that we can try and do something to fix!

image of budding lilac branch in spring

What you need is young new growth. Now if you are a good and regular pruner, your lilac probably blooms well since you take care of it each year. But I confess, I am a procrastinator. I tell myself I am going to prune, but a lot of the time, I just never get around to it. ( There is always another hypertufa pot I want to make or some weeding to do, know what I mean?)

So we have to get drastic to get our blooms back.  You may think ” Oh, I will just get a new bush and start over.”  But you can have a “new” bush from the ashes of the old one. It will rise like a Phoenix, for real.

image of large overgrown lilac bush

No, don’t burn it! Cut it down!

Seriously, drastically cut it back to the ground and get almost all new shoots!  Then those new shoots will have blooms and we are back to blooms at the level we can see them and pick them. Loving it!

image of pruning tools and cut branches on tarp

Timing is the Decisive Factor in Pruning Lilacs

If you want to have your blooms next year, it is crucial to prune in those first few weeks after blooming ends. Ideally, this is when you would do maintenance pruning each year.  But I get so lazy busy, I end up with a ten foot bush with ten blooms on top.

So I have just done a complete rejuvenation on my Old Lilac and I am excited to see what will happen next spring when it is all full of young and new branches. 

How to Make Old Lilacs Bloom Again
Watch this video on YouTube.
My YouTube Channel - Kim's Gardens

I shot a video of my husband and I butchering trimming this Old Lilac almost down to the ground.  We thought we’d need the chain saw, but he couldn’t get it started, so we used some ratching loppers and garden pruners.  (#affiliate link)  Those old branches were about 3″ diameter so it worked ok.  I had some problems when I tried cutting. There is some little pivot that you click when the jaws are open and need to latch down on the cutter, but I don’t get that. I am just not mechanical. So my husband handled the larger ones.

image of water sprinkler on trimmed lilac bush

I did the clean up trimming of the smaller branches, going for an open center. There was one final branch that I think needs to come out and he doesn’t. What is your opinion?  You can check out the branch in question on the video. It is at about 10:45 in the video if you want to check it out. I think it is clear that a woman’s opinion should be the deciding factor. Happy wife, happy life, right?


UPDATE:   We moved away from this home before the spring bloom, but the small bush was just thick with branches and shoots for the leaves when we left in March 2018. I am sure it bloomed really well….Kim


Another update:  I have seen the lilac bush with my own eyes this new season  May 2019 and May 2020 and it is growing well over 6ft high and blossoming nicely. Rejuvenation works!


  1. Lilacs also won’t bloom if they have too much nitrogen. Mulch them with wood chips to adjust that.

    1. That’s great tip for non-blooming lilacs. In my case, mine was blooming but the flowers we so high up, I couldn’t enjoy them. Needed to control the size of the total bush.

  2. I just watched your video and it has made me realize I need to severely trim back some of my old lilacs. I did that to several forsythia bushes that had outgrown their space. I didn’t recognize the leaves on your variety of lilac. They looked closer to my forsythia bushes. My lilacs are the really old-fashioned kind (gifts from friends and relatives that have passed away) and the leaves are more heart-shaped.join

  3. I watched your video and am encouraged to work on my overgrown lilac bushes. I had several overgrown forsythia bushes that I had to cut way back to curtail their growth as they had outgrown or should I say “overgrown” their space. I must say that I thought your bush looked more like my forsythia bushes than lilacs. I didn’t recognize the leaves at all. It must be a variety that I am not familiar with. Mine are the old fashioned kind and the leaves are almost heart-shaped.

    1. It has come out nicely this spring. Lots of branches and should bloom well. But we just sold our home and have moved away, so I won’t get to see it bloom. 🙁

  4. Hi Kim,

    I have a lilac that doesn’t bloom for me. I think it needs more sun but I did not know that they bloom on new wood. Thanks for the great tip!

    1. Hi Patti, So glad I could give you some info that you didn’t know. I was just out looking at the pitiful little bush and I was sort of surprised. It is really leafing out really well. Fingers crossed for spring.

  5. Amy Butler says:

    My experience with cutting lilac way back is, they grow year 1, bloom year 2. Don’t be discouraged if you don’t have blooms the first year.

    1. I will cross my fingers for next spring, but it will probably be the following spring like you say.

  6. Vicki Zwiebel says:

    I should do this to a few around here and we did a couple of years ago, but didn’t take them down near enough. I was afraid. They are very old an I would hate it if something happened to them. I’ll check yours out next Spring and see how they turn out! Happy Spring!

    1. I took it down to about 12-15 inches. So drastic but it had to be done. If I can’t enjoy the blooms, this one needs to be fixed or replaced. Wish me luck.

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