We have a beautiful, neglected, way overgrown lilac in our back yard that I am currently working on whipping into shape. I have never trimmed a lilac before (except the other one in the middle of the yard that I turned into seven sticks with leaves on top - it was a concept piece), and I would like to make it look nice and full and round, except without being all choked on its own sticks and stuff.
Any suggestions? My husband thinks just taking out the dead branches will be enough, but I don’t think so - I think we need to get into the heart of the bush and take some fairly large branches out, to get the air into it properly, and revive it for next year. I’m not too worried about cutting the lilac way back, because that just seems to encourage them.
You can cut back about a third of the branches. Then next year cut back another third, and the next year another third. It’s good to get some air in there. Some lilacs never need pruning but if they do, the 1/3 method is a good one. Next year you might see less, or no, flowers, because you will probably be cutting away some future blooms. It’s actually somewhat late now to prune lilacs; you should have done it right after the blooms faded (probably late May/early June), so it might be that next year you’ll get no blooms. But if it needs it, I’d do it now anyway.
What blooms? Our late frost killed virtually all of them this year.
Yeah, I realize it’s late for trimming, but the tree hasn’t been trimmed in years, so I figure getting the rot out of the middle will offset the lateness of the trimming.
When you say cut back a third of the branches, do you mean cutting the large trunks, too, or a third of the new growth, or a third of everthing sticking up in the huge mound that is my lilac?
This is going to sound drastic and savage. A lilac is supposed to have a certain shape; narrow bundle of branches gracefully arching out to a broad top, a bit like broccoli. Most kinds of pruning will destroy that look. Cut the whole thing down to about a foot high. A mature bush has a huge, vigorous root system, and it will come right back in a couple of years to a graceful bush, half the size of what you started with.
I meant cutting back a third of the total of the branches, down to the trunk. (Not take a 3 foot branch and cut off 1 foot; cut the whole branch down.)
You can also cut the whole thing down to a foot high but I wouldn’t do it. There are different opinions on pruning lilacs and mine is to not do that. It’s also accepted to prune a lilac into the shape of a small tree, which is also very pretty.
You should good “how prune lilac” and see what comes up. You’ll see the difference in pruning recommendations.
I think cutting a third of the branches would be about right (excepting the really large trunks). The more I get into the heart of the lilac, the more composting leaves I’m pulling out - some of the branches themselves are rotting, and that can’t be good for the shrub. My goal is to get all the old dead branches and all the decaying leaves out of the middle, leaving a nice, airy middle.
My advice is to cut it back to hardwood, and then some more like AskNott suggested.
Be ruthless, and you will be rewarded with a glorius bush in no time at all…just be careful about WHEN you cut it back. It might be best to wait until autumn (fall) as is recommended with deciduous plants. I think cutting it back at the height of summer might create some problems with burning of new growth (depending on your climate of course).
Judging from how it’s been going so far, I’ll probably be done trimming it sometime in fall.
The problem with a serious trim is that this bush shades our bedroom window, and my husband doesn’t want the bush trimmed so seriously that anyone walking down the back lane can stare in our window (which is a valid point). The other bush that I trimmed down to seven sticks is coming back wonderfully; that one will be a beautiful, full shrub by the end of next summer. I love lilacs; such an exuberant, tough plant.
I just want to emphasize this bit. My mother cut hers back at the wrong time (spring) and it didn’t bloom again for nearly 20 years.
Personally, though, I’m a huge fan of the wild-looking hedges that are common where I live as opposed to the single bush growing here and there so I’ve never given a thought to trimming them.
This, from someone whose wife wanted a lilac completely removed from the side of the house. A lilac bush at least 12 feet high, with stern and woody branches.
Me, being too lazy to dig the behemoth out of the ground, I sawed all branches off about six inches above the ground, which is about as close as I could manage it.
“It’ll die off and rot away by spring,” says I. “Good work,” says she.
Come spring, no less than 345 green and wiry shoots sprout from the sawed-off stumps, each sporting an array of green leaves, and later, sprigs of purple fragrant flowers. In a nice, bush-shaped display.
