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Planting and Growing Lilac Bushes

purple Yankee Doodle Lilac flowers

Huge blooms, wonderful scent.

Image Credit:
Wally Patrick
Botanical Name
Syringa spp.
Grown as
Perennial
USDA Zones
3a
3b
4a
4b
5a
5b
6a
6b
7b
Toxicity
Non-toxic
Sun Exposure
Full Sun
Partial Sun
Water Needs
Moderate
Height
6-10 feet
Spread
6-10 feet
Soil pH
Neutral
Bloom Time
Spring
Summer
Flower Color
Blue
Pink
Purple
Red
White
Yellow
Special Features
Container-Friendly
Cut Flower
Fragrant
Attracts Butterflies
Attracts Hummingbirds
Attracts Pollinators
Deer-resistant
Rabbit-resistant
Resilience
Cold Hardy
Drought-Tolerant
Plant Type
Shrubs and Bushes
Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

Lilacs truly smell like spring! Lilacs are among the most carefree spring-flowering shrubs and provide a sweet, haunting fragrance, too! Learn how to plant, grow, and prune your lilacs.

Lilacs, said to symbolize the joy of youth and associated with spring’s awakening, are hardy, easy to grow, and low-maintenance. Although they can reach heights of 5 to 15 feet (or more), depending on the variety, the ideal lilac shrub produces flowers at eye level—all the better for enjoying their sweet fragrance.

The common lilac, Syringa vulgaris, is well loved for its toughness, reliability, and fragrance. In fact, lilacs are so tough that they can grow for 100+ years, often outliving the homes they were planted around. The fragrant flowers are good for cutting and are attractive to butterflies.

While the blooms are usually lilac/purple in color (from very pale to very dark), there are also lilac varieties in white and cream and even pink and yellow. Individual flowers can be single or double.

In northern states, lilacs bloom for about 2 weeks from mid- to late spring. However, there are early-, mid-, and late-season lilacs, which, when grown together, ensure a steady bloom for at least 6 weeks.

Planting

When to Plant Lilacs

  • Like most shrubs, lilacs can be planted in either spring or fall, although the latter is preferred.

Where to Plant Lilacs

Lilacs thrive in fertile, humus-rich, well-draining, neutral to alkaline soil (at a pH near 7.0). If your soil is in poor condition, mix in compost to enrich it. (Learn more about soil amendments and preparing the soil for planting.) Choose or prepare a site that drains well. Poor drainage or pooling water can cause “wet feet,” potentially leading to root rot, stunted growth, and/or failure to flower. Test soil drainage by digging a hole 8 inches in diameter and 12 inches deep. Fill it with water; if it does not drain within an hour, choose another spot.

For the best blooms, lilacs should be planted in full sun, which is defined as at least 6 hours of sunlight each day. Given less, they will not flower as well. 

How to Plant Lilacs

  • If you’re lucky, a friend will give you a sucker, or offshoot, of the root system of one of their plants. The sucker will look pathetic at first, but dig a hole, backfill it with soil, and stick the sucker in. Then, water and wait. In 4 or 5 years, you’ll be rewarded with huge, fragrant blossoms.
  • Transplanting nursery-bought lilacs is also easy. If it’s container-grown, spread out the roots as you settle the plant into the ground; if it’s balled or burlapped, gently remove the covering and any rope before planting. Set the plant 2 or 3 inches deeper than it grew in the nursery and work topsoil in around the roots—then water in. Then, fill in the hole with more topsoil.
  • Space multiple lilac bushes 5 to 15 feet apart, depending on the variety.

Growing

  • Each spring, apply a layer of compost under the plant, followed by mulch to retain moisture and control weeds.
  • Water during the summer if rainfall is less than 1 inch per week.
  • Lilacs won’t bloom if they’re overfertilized. They can handle a handful of 10-10-10 in late winter, but no more.
  • After your lilac bush has finished blooming, spread some lime and well-rotted manure around the base. Trim the bush to shape it and remove suckers at the same time.

How to Prune Lilacs

  • Lilacs bloom on old wood, so it’s critical to prune in the spring right after they bloom. If you prune later in the summer, you may be removing the wood. Note: If your lilac flower clusters are getting smaller over a few years, it’s time to prune!
  • Every year after bloom, remove any dead wood. Prune out the oldest canes (down to the ground). Remove the small suckers. Cut back weak branches to a strong shoot. Cut back tall canes to eye height.
  • The ideal lilac shrub has about 10 canes. If your lilac is old and in really bad shape, remove one-third of the oldest canes (down to the ground) in year 1, half of the remaining old wood in year 2, and the rest of the old wood in year 3. Another option for old lilacs is to chop the whole thing back to about 6 or 8 inches high. It sounds drastic, but lilacs are very hardy. The downside to this option is that it takes a few years to grow back. The upside is less work and more reward, as the lilac will grow back, bursting with blooms.
  • It must be recognized that severe pruning results in the loss of blooms for 1 to 3 years. For these reasons, a wise pruning program aims to avoid severe and drastic cuts by giving the bushes annual attention.
  • Good Sucker Sense: Gertrude Jekyll, the 19th-century no-nonsense English horticulturist (1843–1932), advocated a strenuous exercise: “When taking away suckers … it is better to tear them out than to cut them off. A cut, however close, leaves a base from which they may always spring again, but if pulled or wrenched out, they bring away with them the swollen base.”

Pests and Problems

  • Prone to attack by slugs and snails.
  • Powdery white mildew may appear after a summer of hot, humid weather. It may be unsightly, but it does no harm. Ignore it.

Types

For early flowers, try Syringa x hyacinthiflora hybrids; they bloom 7 to 10 days before S. vulgaris. Its fragrant blooms attract butterflies and hummingbirds.

The most common and fragrant lilacs are of the S. vulgaris variety:

  • Try ‘Charles Joly’, a double magenta flower, an early bloomer.
  • Mid-season lilacs include ‘Monge’, a dark reddish purple, and ‘Firmament’, a fine blue.
  • Late-season beauties include ‘Miss Canada’, a reddish-pink, and ‘Donald Wyman’, a pink-purple flower.

Uncommon types/varieties include … 

  • S. x ‘Penda’ Bloomerang Purple: flowers in spring, pauses, then flowers again from midsummer through fall.
  • Although common lilacs love cold weather, a few thrive as far south as Zone 8, including cutleaf hybrid S. x laciniata, with fragrant, pale lavender flowers, and S. pubescens ssp. patula ‘Miss Kim,’ with pale, lilac-blue blooms that fade to white.

Small Lilacs
For gardeners, especially those in urban spaces, who just don’t have the room for the traditional larger lilac, there are compact varieties! They’ll even grow in a container on your patio or balcony.

  • ‘Baby Kim’ grows only 2 to 3 feet high (and 3 feet wide) in a nicely rounded shape with purple flowers that attract butterflies. Extended hardiness from Zones 3 to 8.
  • ‘Little Lady’ (S. x) is a compact lilac that matures to 4 to 5 feet tall and wide with dark pink buds that open to lilac-pink flowers. Hardy in Zones 2 to 7.
  • ‘New Age Lavender’ and ‘New Age White’ (S. vulgaris) are super-compact, growing from 4 to 5 feet tall and wide, and bred for mildew resistance. Their fragrant flowers attract butterflies and hummingbirds. Hardy to Zone 4.

See more lilac varieties!

Wit and Wisdom

  • To improve the flowering of lilacs, keep the grass from growing around them. A 16- to 24-inch circle of landscape cloth placed around the bushes and covered with bark or stone will keep the grass down.
  • Force a winter bouquet from cut branches of lilac. Bruise the cut ends and set them in water. Spray the branches frequently. Keep them in a cool place until they bloom, then move to a warmer area for display.
  • Poet Walt Whitman thought of lilacs when Abraham Lincoln died: 
    ”When lilacs last in the dooryard bloom’d … I mourn’d, and yet shall mourn with ever-returning spring.”
  • Lilacs supposedly symbolize the joy of youth. Learn about more flower symbolism here.
  • The lilac belongs to the olive family, Oleaceae.
  • Lilacs are the state flower of New Hampshire.

Shrubs and Trees

About The Author

Catherine Boeckmann

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann loves nature, stargazing, and gardening so it’s not surprising that she and The Old Farmer’s Almanac found each other. She leads digital content for the Almanac website, and is also a certified master gardener in the state of Indiana.

Read more from Catherine Boeckmann

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Comments

<span>Anonymous</span> Thu, 04/05/2012 - 19:09
I WANT TO PLANT THIS THIS SPRING. WE ARE IN ZONEE 4.
<a title="View user profile." href="/author/editors">The Editors</a> Fri, 04/06/2012 - 11:36
According to some sources, it may take up to 7 years after being transplanted for lilacs to bloom. Also, lilacs should be pruned in the spring, immediately after they blossom. If they are pruned later in the summer, you may be cutting off the new growth that has the flower buds for the following year.
<span>Anonymous</span> Sun, 04/01/2012 - 17:14
my tree bloomed tons last few years, everyone else's are flowering but mine won't even show buds. Help. I love these plants and want flowers
<span>Anonymous</span> Sat, 05/12/2012 - 07:45
I had the same issue with two large bushes both over 10 years old. Both had robust growth in years prior. Last year I was away for their blooming season and missed out on the amazingly fragrant flowers which I always cut to put into vases for myself and all my friends since there was always so many. I suspect the low flower rate this year was caused by the fact that I did not cut the flowers the prior year and I didn't prune back after the flowering.
<a title="View user profile." href="/author/editors">The Editors</a> Tue, 04/03/2012 - 16:44
Also, be sure to snip back the spent blooms right after they fade (back to the leaf, just past the bloom). This can take a while but it will rejuvenate your lilacs.
<a title="View user profile." href="/author/editors">The Editors</a> Tue, 04/03/2012 - 16:25
The most common reason lilacs stop flowering is pruning at the wrong time of the year and too much nitrogen fertilizer. Lilacs flower on wood grown the previous season, so any pruning must be done immediately after the shrub blooms. Pruning in summer or fall or early spring will remove flower buds. Prune as directed on above page and withhold fertilizer.
<span>Anonymous</span> Tue, 03/27/2012 - 20:42
we planted our bushes 2 years ago and had a frost i mistakenly covered them with black trash bags and they burnt since then the bushes look very healthy but have never bloomed will they ever?
<a title="View user profile." href="/author/editors">The Editors</a> Wed, 03/28/2012 - 12:29
Some varieties of lilacs need a few years to mature. Other reasons for not blooming: A late freeze, too warm a winter (lilacs need chilling), lack of sunlight (6 hours of full sun needed), overfertilizing (not needed), soil that's too acidic (get a soil test and amend with lime if needed), and incorrect pruning (the most common mistake). Pruning helps a lilac flower. Avoid drastic pruning while your lilacs recover. See the pruning tips above.
<span>Anonymous</span> Mon, 04/02/2012 - 20:07
How big do the roots get? Can I plant it next to my house near my bedroom window?
<a title="View user profile." href="/author/editors">The Editors</a> Tue, 04/03/2012 - 16:41
Plant the lilacs about 12 feet or more from the foundation to avoid worry. Lilac roots aren't invasive though they can ramble and lilacs need room to grow in all directions. The roots are about one to one-half times the length of the branches. A 10-foot shrub would have roots about 15 feet in every direction. However, the roots aren't invasive and don't worry too much about foundations.