How to prune a lilac tree? ( Find Out!)

Last Modified

February 24, 2023 by Hirah Ehsan

Spring is in the air, right? And, you know spring is the best season for pruning a lilac tree. You can prune your lilac tree and use it for making a bouquet. Isn’t it interesting?

Arborists suggest, nipping off the longest stems of the trees promotes their growth. Also, remove weak stems at the base. You need to follow the rule of three (explained later in the article).

The lilac tree is the one everyone loves to grow in their garden. Why? Because it looks beautiful. But only a few know how to take care of it. People leave it unattended and grow older.

Do you love your tree? Do you want to grow it healthy? Then prune your trees once a year at least. Want to know more about pruning and its benefits? Keep reading the article.

I strongly recommend pruning by hand with perfect tools. The tools include hand pruners or shears. You are supposed to trim a lilac tree after it’s done blooming. Let’s explore more about it.

How to prune a lilac tree?

Lilac tree deserves pruning to breathe and live healthily. But let’s first see how to prune them.

  • Dead-head flowers

Deadheading means, removing the flowers that are dying out. You use pruners and cut blossoms and the first set of leaves. You can create amazing indoor bouquets or decorations from it.

  • Tip-off Triads

You have to observe the long stems and use a clipper to cut them. It helps in reducing the overall- weight of the shrub.

If you have observed lilac closely, you may have seen it produces a triad of stems. What’s your job here? Your task is to remove the spent blossom in the middle back to where the three branches connect.

  • Removing the 1/3 of the thickest stem

Lilac is considered a multi-shrub system. they are this way for maximum bloom and fruit production. So in this process, we focus on removing the oldest wood as it is less productive.

Some people say that if you want to make your lilac flowery then you should remove any major branches that are bigger around your thumb. However, in my opinion, you should let them grow thicker.

Lilacs can be pruned to a height of 2-3 feet. If you have a large bush, it may be necessary to cut it back to 1-1/2 to 2 feet to keep it from getting too tall.

But yes do remove thick old woods to encourage growth. If your trees have a lot of stems, consider on;y one by third of them this year to remove.

  • Removing suckers

The fourth step in the typical pruning cycle is to remove any thin straggly suckers coming up from the base of the shrub that is either crossing or too far from the center of the shrub.

If we talk about taking them out. When taking them out you have the option to snip them at the base of the shrub or take a shovel and jab in it and then remove them.

Pruning Lilac Bushes

Do you want to maintain the form and create a balance between new flowering shoots and older stems? I mean why not? So, a little effort is required on your part.

Let’s find out together what you need to know about how to prune a lilac bush.

Before diving into the process, I would like to tell you about the tools you need. The tools include a bypass pruner, loppers, hand gloves, glasses, a pruning saw, or Stepladder.

First of all, observe the bushes. You will see certain bushes interfering with the growth of the plant. Make sure to prune them.

The next step is to make a clean cut just above a new shoot or bud. Cut the bud in such a way that you want to shape it. It is done to give them a proper form and structure.

Moreover, pruning can be divided into two types. You can follow any style of pruning to attain the desired results.

Two main types of Pruning

Lilac pruning can be generally broken down into either maintenance pruning or rejuvenation pruning. Let’s explore each of them

  1. Maintenance Pruning

Maintenance pruning includes the removal of dead, diseased, or broken stems. you can also remove spent flowers from your lilac to enhance its appearance.

In maintenance pruning, we try to cut back to a proper lateral system and an outward-facing bud. Mainly, it focuses on the shape of the tree.

  • Rejuvenation of Lilacs

Folks often assume that older lilac has stopped flowering due to age.  It is a misconception. If your tree went unpruned for many years and looks overgrown it doesn’t mean that its growth has stopped.

Now, what’s the solution?

You can simply remove the older canes that are 2” in diameter. It encourages rejuvenation. You will have to apply the rule of third. It means removing approximately one-third of the growth each year for three years.

It gives the shrub a chance to get back to life. It grows from a shorter shrub to a longer one. Use water and fertilization to boost the process.

When to prune a Lilac?

 Being an arborist, I have always been asked what is the right time to prune a lilac tree. Listen to my advice carefully.

Don’t prune your lilac until it’s fully in flower, little blooms take a full year to grow. If you prune it before a year completes then you remove the blooms. They exist there, even if you don’t see them.

Nevertheless, what you can prune at any time of the year are dead stems.

Truth about Lilacs

Sometimes, the suckers start growing from the base and they are growing throughout the garden which is a real issue. If you want to get rid of it, I would suggest you pull them off right away.

What next? Then you are going to bury them in the newspaper. You can use seven layers of newspaper over the top of them around the plants it is a great way to get rid of your lilacs. The newspaper smothers the lie locks.


Lilac trees add beauty to our backyards. At least they deserve to be taken care of. A brief detail of pruning and its benefits has been mentioned above in the article.

No, it is your responsibility to show your genuine love for your lilac tree by pruning and trimming them. That’s it, folks! Happy pruning!

People Also Ask

What happens if you don’t prune lilac bushes?

The question is very genuine and the reason is very obvious. If you leave lilac bushes to grow on their own then they will lose the balance between older stems and new flowering shoots. Because lilacs will eventually only flower at the tips of their uppermost branches.

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