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How to Prune Lilac Bushes

By Yolanda Vanveen ; Updated September 21, 2017

Pruning a lilac bush involves chopping down each branch one third down to make room for more growth the following year. Trim lilac bushes, cutting only one third of the whole thing away, with tips from a professional gardener in this free video on gardening.


Hi, this is Yolanda Vanveen, from vanveenbulbs.com, and next we're going to learn all about how to prune our lilac bushes. Now, as you can see this lilac bush has not been pruned for many years. It's on the border with my neighbors and she doesn't really see it from her side and I've never done anything to it so it's kind of overgrown and it's not looking that great. It's not been watered, it's not been maintained but it's still alive, that's the glory of lilacs, they will survive almost anywhere. So what I'm going to do is I'm going to, pretty much, just hack it back. It's the end of Summer and I want it to have lush growth for next year and I want to get lots of blooms. I probably should have hacked it back right after it was done blooming but, as in anything else in gardening, do it when you get to it because life is not about rules, it's about us taking care of things when you get the chance anymore and I've got the chance today, so lets chop it. The rule of thumb is to make sure and not chop it back more than one third so, as you can see, it's quite big and out of control so I'm going to try to chop it down one third down but I do have a tendency to chop even more. So, if it's a little bit more than that, at this point, I'm not going to worry about it because I know it'll grow in even better next year. So, when I'm cutting back, I'm trying to follow that one third rule, you can always go back the next year and go another one third, so I'm just cutting every branch about one third down. These, which are really dead and lanky, I am just going to whack back but you don't want to just go back to the stem, you're thinning it out. The whole goal is to get more air in there so I am just going to keep chopping. It's best to chop, actually, right where, like this looks like new growth, it's alive, this other part does not look good so it's best to cut at an angle right near where that new growth is and that way it'll probably shoot out from the other side too. Now, that looks really bad almost all the way to the end but still I'm trying not to chop it too much either. Like I said, you can always go back next year and chop some more. My key, pretty much, with pruning things, is just going to town especially on this one. It's really not going to do much for years and years. Look, I see some new growth right there and I see some new growth right here, it's actually still alive, believe it or not, so I am just going to cut right above that line. Of course, this is a pretty old tree so it's not cutting very well so you just kind of keep working at it, you probably could have sharper tools, as well, but this seems to be working. So yes, it's not going to look like much this year, I understand that, but it'll probably die eventually, it's not getting much water and I bet if I keep whacking this, it'll look good for next year. So, just keep going through the whole thing and, pretty much, just try to keep, like we said, some new growth and over here there's more too. As you can see, I'm just going to whack this baby back and next year it will fill out and I know it will look just beautiful.


About the Author


Yolanda Vanveen is a third-generation flower grower and sustainable gardener who lives in Kalama, Wash. She is the owner of VanveenBulbs.com, selling flower bulbs on the Internet, at garden shows and at farmers markets in the Pacific Northwest for more than 20 years. Vanveen holds a degree in communications and international studies from Linfield College, and is a graduate of the WSU Master Gardener Program. Vanveen represented the United States at the 2006 Indigenous Bulb Society Symposium in South Africa and has been featured on the PBS show Smart Gardening, demonstrating which way is up with flower bulbs.