#ProPlantTips: Pruning and Caring for Lilacs

#ProPlantTips: Pruning and Caring for Lilacs

lilac header

Like a breath of fresh air and the promise of warmer weather ahead, Lilacs are highly anticipated blooms each spring!

These are some of our favorite flowering shrubs here at Nature Hills Nursery and our horticulturists want to help you know the best ways to keep your plants blooming and looking their very best!

All About Lilacs common purple lilac

Flowering Lilac bushes (Syringa) are low-maintenance, easy to grow, and are very hardy plants! They are among the most fragrant flowers in the plant world! You’ll find a fabulous range of Lilac for sale right here at Nature Hills Nursery. In addition to being fantastically fragrant, Lilac bushes are rugged and long-lived. This makes Lilac bush care a breeze.

Larger shrubs offer good summer shade and privacy once they have reached their mature height, and provide screening from the neighbors, as well as block wind! Pollinators adore these blooms, so bees and butterflies will arrive in droves seeking out the nectar! They are fantastic cut flowers for perfuming your home and are just an old-fashioned standard flowering shrub and herald of summer.  butterflies on lilacs

Most Lilacs perform best between USDA hardiness zones 2 to 8, where longer hours of winter chill hours are available. Lilacs simply will not bloom if they’ve not had the required amount of chill. In warm winter zones, you can get the look of a Lilac with California Lilac (Ceoanthus).

Why and When to Prune Lilacs

The average size for a Lilac bush is approximately 6-10 feet, so tackling the job of trimming, shaping, and pruning Lilacs is easiest when you know how. Pruning should be done immediately after the flowers have died off. With a little pruning knowledge and how to replenish the old wood with new shoots - these shrubs can last a lifetime!

Plan to prune your Lilacs immediately at the end of the blooming season, which occurs in early summer. Pruning too late will result in a reduction of blooms in the next season, or removing them entirely! Pruning too early will lessen the amount of time you have to enjoy your bush or Lilac tree during the season.

trimming a lilac bush infographic

You will need:

  • Pruning shears
  • A small saw
  • Gardening gloves

How do you trim a Lilac bush?

  1. Decide on your Lilac bushes height - Prune fewer old stems at the top of the bush if you prefer to retain them as tall bushes - Since the older stems produce the flowers, trimming too many of them will cause the Lilac bush to have fewer blooms.
  2. Clip off the dead flowers - Spent Lilac flowers are primarily located at the top of the bush.
  3. Trim shoots/suckers near the ground - Remove any suckers that develop too far away from the base of the plant if desired.
  4. Reach into the bush and clip a few larger stems - This will allow more sunlight to reach the inside stems.
  5. Prune dead or unhealthy-looking stems- These are the stems that are broken, withered and often hanging haphazardly on the plant.
  6. Trim branches - Focus on cutting the branches that stick the farthest out from the bush and any branches that are twisted around each other. Use the saw to cut the branches if your Lilac plant is older and the branches are thick.

Frequently Asked Questions

Can Lilacs be cut back hard? cut back lilacs hard

How do you rejuvenate old Lilacs? Say your older Lilac shrub has become sparse and leggy, requiring something more severe than just a trim. Renewal pruning and drastic changes may need to be done to freshen up the entire shrub, but it will be worth it.

Maybe your Lilac is simply old and overgrown and you really need to rejuvenate it. You can let it bloom first if you like, but if you can't wait - you can cut out the oldest, fattest stems right down to the ground. Leave the younger, thinner stems in place just as you would for renewal pruning any other shrubs. 

Maybe your plant is really overgrown? Lilacs are very forgiving and will respond beautifully if you cut all of the stems down to the ground and let all new growth develop from the roots. 

Should you cut back Lilacs?

Yes! Pruning Lilac bushes not only helps add fullness and branching but also shapes the plant and encourages new growth. You’ll keep large shrubs in check and small shrubs neat and tidy.

Transplanting Lilac Bushes primrose lilac

You can transplant young shrubs quite successfully! Read more in our Garden Blog Here!

Mulching and Fertility

It is best to add a 3-4 inch thick layer of Arborist bark chips as mulch over the surface of the root system, out to the dripline of your shrub or Lilac tree. This not only helps maintain soil moisture, and adds fertility but it also helps keep weeds down. 

Use a general-purpose fertilizer in early spring, as soon as you see new growth forming, to promote blooming. Do not give flowering shrubs too much nitrogen since this will result in too few blooms! And avoid applying lawn or high-nitrogen fertilizers too close to these plants! 

Soil and Water wet soil with x across

Lilacs do not like wet soil over a prolonged period of time. The roots run very deep, so if there is an extended drought period, water infrequently but thoroughly. They prefer organically rich, slightly acidic soils with good drainage. Add compost or arborist wood chips to maintain a 3 - 4 inch layer as mulch over the roots as needed to help retain moisture.


Lilacs bloom best in full sun, so when planting a Lilac, be sure to select an area with at least 6 hours of direct sunlight per day. For older shrubs that may have had large trees grow up around them and begin shading them out, try pruning out a few limbs to let the sunshine through for your Lilac.

Enjoy Your Lilacs! tree form of lilac

From large, impressive shrubs to smaller dwarf varieties, and even unique tree-form specimens and Bloomerang® reblooming varieties, the Lilac family's diverse colors and sizes will fill your world with varied beauty that lasts for decades! Let NatureHills.com help you keep your shrubs looking their very best!

Happy planting with Nature Hills Nursery!

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