Lilacs

Huge blooms, wonderful scent.

Credit: Wally Patrick
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Botanical name: Syringa

Plant type: Shrub

USDA Hardiness Zones: 3

Sun exposure: Full Sun, Part Sun

Soil type: Any

Soil pH: Neutral to Slightly Alkaline

Flower color: Red, Pink, Yellow, Blue, Purple, White

Bloom time: Spring, Summer

Who doesn't love lilacs? The ideal lilac shrub has about 10 canes and produces flowers at eye-level—all the better to enjoy that sweet, haunting fragrance.

Lilacs do come in seven colors but most are familiar with the common lilac, Syringa vulgaris, which blooms in the northern states for 2 weeks in late May. However, there are early-, mid-, and late-season lilacs, which, when grown together, ensure a steady bloom for at least 6 weeks.

Lilacs are hardy, easy to grow, and low maintenance. They can grow from 5 to 15 feet tall, depending on the variety. The fragrant flowers are good for cutting and attractive to butterflies.

Lilac Pictures

Click slideshow below to enjoy 7 lovely lilac pictures taken by our Almanac readers!

Planting

  • Grow lilacs in fertile, humus-rich, well-drained, neutral to alkaline soil (at a pH near 7.0). If your soil is in poor condition, add compost to enrich.
  • Select a site where your lilac will get full sun—at least 6 hours. If lilacs don't get enough sun, they will not bloom well.
  • Make sure the site drains well. Lilacs don't like wet feet and will not bloom with too much water.
  • Plant in either spring or fall, although the latter is preferred.
  • If you're lucky, a friend will give you a sucker, or offshoot, of the root system of one of his plants. Your sucker will look pathetic at first but just 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 lilacs from a nursery 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, gentle remove it 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. Water in. Then fill in the hole with more topsoil.
  • Space multiple lilac shrubs 5 to 15 feet apart, depending on the variety.

Care

  • 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.

Pruning 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. Here's a tip: If your lilac flower clusters are getting smaller, 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.
  • If your lilac is old and in really bad shape, remove one-third of the oldest canes (down to the ground) in year one, half of the remaining old wood in year two, and the rest of the old wood in year three. 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 one to three years. For these reasons, a wise pruning program aims to avoid severe and drastic cuts by giving the bushes annual attention. 

Pests

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

Recommended Varieties

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

  • For early bloom, try 'Charles Joly', a double magneta.
  • Mid-season lilacs include 'Monge', a dark reddish purple, and 'Firmament', a fine blue.
  • Late-season beauties include 'Miss Canada', a reddishpink, and 'Donald Wyman', a single purple.

Although common lilacs love cold weather, a few thrive as south as Zone 9, among them the cutleaf lilac, a fragrant pale lavender. Syringa patula 'Miss Kim' is a graceful shrub with pale lilac-blue flowers that fade to white.

Special Features

  • Attracts Butterflies

Wit & 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 hall mourn with ever-returning spring."

Comments

Tiny blooms

By Almanac Staff

The size of the flowers may be caused by the weather this past winter and early spring.
Too much nitrogen in the soil can also cause poor blooming. Use a fertilizer high in phosphorus. A tip from the Almanac archives is to spread your fireplace ashes around the lilac bush for bigger, better blooms.

Question about blooming

By Anonymous

We have had a lilac tree for about 3-4 years now. It has yet to bloom. It's aprrox. 7' in height. After we bought it and planted it, we found a better spot for it so decided to transplant it. I thought perhaps it was in shock. The leaves look great as does the tree itself. Any help would be greatly appreciated. I have no idea what kind of lilac it is though. Thank you in advance. Lesley

Lilac not blooming

By Anonymous

I had the same problem. Lilac plant beautiful but would not bloom. I removed trees that kept the lilac in the shade and
fed it lots of lime. The next year it bloomed.

why lilac is not blooming

By Almanac Staff

If your lilac plant is only 3 to 4 years old and you have never seen blooms on it, it may not be mature enough to produce flowers. You may need to be patient and wait another year. Or, it may be due to other factors. Does your new location have full sunlight and dry soil? No sun, no blooms. Did you plant too deep? Is it the right type of lilac for your region? Are you using a fertilizer with too much nitrogen? And you pruning incorrectly--see this page on how to prune lilacs so that you do not remove its very buds for next next year's growth.

planting Lilacs

By Anonymous

I live in the tri-corner of CA, NV, and AZ. I want to plant a lilac in my barren backyard. I have many wind chimes and bird baths but no trees or other bushes, back yard is very sunny and windy except close to the house. What lilac is best for my area and conditions?

lilacs for southwest

By Almanac Staff

Given the heat, try Persian lilac or Chinese lilac. They are low-chill lilacs (which normally need a chill) and best for desert areas.

pot instead of ground?

By Anonymous

Will I stunt the growth (blooms) of Charles Joly shrub if I plant it in a huge pot instead of in the ground?

Lilacs in pots

By Almanac Staff

This shrub appears to be fine for containers: http://www.buyplantsonline.com/charles-joly-lilac-plant-one-gallon.html

clay and dirt

By Anonymous

I bought a Charles Joly lilac bush from a nursery and was ready to plant it, but when I started to dig the whole, I found that about a foot into the dirt, I hit clay and rock. Now I'm afraid to plant it there. Although there are trees and bushes growing all around. Should I find another place?

planting lilacs in clay

By Almanac Staff

Lilacs are actually one of the plants that will tolerate clay soil with a pH of 6 to 7. Working compost in with the soil will help provide nutrients.
In terms of proximity to other trees and shrubs: Be sure they are spaced properly. A Charles Joly Lilac is a medium-size lilac shrub and should be spaced 4 to 7 feet apart to allow it to spread. Also, lilacs prefer 5 to 6 hours of sun so you don’t want them shaded by other trees and shrubs.

Dead buds?

By Anonymous

I am not sure but my lilac has dry ends on 3/4 of the stems this year-I have had them before-it visually looks like a spent bud-open with nothing in it-they snap right off-I don't know why one has to trim back the spent flowers every year-My aunt has been gone for many years-she always had large full lilac bushes-they are still that way at her place-house is gone but lilacs are still there-never get pruned or treated in any other way-they are gorgious-I even took one to plant at my home-whats up with the dry ends and whats your feelings on my aunts lilacs-never been touched-

Mild winters and few blooms

By Anonymous

The past few winters have been very mild (I'm in Maryland, zone 7a) and my lilacs are barely putting out any flowers. Is there anything I can do to encourage blooming despite this?

Lilac Bloom

By Almanac Staff

There are five main reasons that lilacs fail to bloom: insufficient sunlight, too much nitrogen fertilizer, improper planting (planted too deeply), improper pruning (pruning at the wrong time) or winterkill of the flower buds. Also, lilacs will typically not bloom the season after a harsh pruning, so you may need to wait until next year before you see flowers. If nothing works, you might take a sucker from your lilac bush and try growing it in a new location.

When & which ones to plant

By Anonymous

We are outside Philadelphia & want to plant lilacs Any suggestions as to which types work bests & when is then best time to plant?
Thanks

Lilac varieties Philadelphia PA

By Almanac Staff

On variety, it depends on whether you want a tree, shrub, border, etc. A classic is the common lilac (Syringa vulgaris). It's 7 to 15 feet tall and spreads 6 to 12 feet once grown. For a smaller lilac, consider the Persian lilac tree. Then there is the ‘Miss Kim’ (Syringa patula), a hardy compact shrub (five feet high by five feet wide). April and May are good times for planting. Enjoy the lovely lilac blooms!

replant

By rhenn

My mom has a lilac bush that has been outside her bedroom window for at least 50 years. We are selling the homestead. I would like to known if you can take a cutting from the lilac bush and put in my
yard so I can always think of mom with the lovley lilacs of my childhood?

old lilacs

By Anonymous

My Mom has a lilac bush that has been near her bedroom window ever since I can remember it must be at least 50 years old?. We are selling her house but I would like to know if you can take a cutting from this and plant in my yard to remember her by?

Old Lilacs

By Anonymous

Established lilacs such as this will have smaller off shoot plants growing around the perimeter of the bush. You can easier dig up some of the smaller lilacs plants growing around the main bush. The roots are not very deep - less then 6". Don't feel timid to only dig up a lilac plant that is a foot high - you can easily replant ones that are 3 to 4 feet high - just looked for slender upright growth.

These replanted lilac bushes will be smaller and resemble a small flowering tree until they begin to fill out over the years.

I moved an established lilac bush which was over 6' x 6' without in sections without damaging it (it was over 20 years old). Lilacs are really a single bush but a cluster of bushes which lend themselves to be relocated in desired.

Help!!

By Anonymous

My Aunt gave me a lilac cutting eight years ago. It has only bloomed once. The bush is still very small. What do I need to do?

The usual reasons that I

By Almanac Staff

The usual reasons that I lilac languishes is: too much shade or too much nitrogen. Move the plant if needed and make sure you fertilize correctly. One way to get your hydrangea blooming is to drive a spade into the ground around the lilac--about where its foliage ends. Do this in a circle around the lilac about 6 times.

hOW MANY YEARS DOES IT TAKE FOR LILACS TO BLOOM AFTER PLANTING.

By Anonymous

I WANT TO PLANT THIS THIS SPRING. WE ARE IN ZONEE 4.

According to some sources, it

By Almanac Staff

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.

lack of bloom

By Anonymous

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

lack of bloom

By Anonymous

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.

cut spent blooms

By Almanac Staff

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.

lilacs not blooming

By Almanac Staff

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.

we planted our bushes 2 years

By Anonymous

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?

Lilac Care

By Almanac Staff

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.

Lilac roots

By Anonymous

How big do the roots get? Can I plant it next to my house near my bedroom window?

lilacs near house

By Almanac Staff

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.

lilac blooms

By Catherine Boeckmann

As you figured out, cover with cloth or fabric, not plastic. Lilacs are super duper hearty. I'm sure it will be fine. There are tips above about how to encourage blooms. When you prune/cut down a lilac, it only wants to bloom more!

weather requirements

By Anonymous

We expect a frost, does anything need to be done to protecr our lilac bushes? they have started to bloom.

thanks

lilacs and frost

By Almanac Staff

Most lilacs are quite cold hardy (to USDA zone 2) and the plant itself will be fine. However, if you have buds already (given this strangely warm winter), you can throw a cloth sheet over the bushes if they're not too big. The buds are damaged easily. Either you'll lose the flowers totally or the panicles will not be filled out---dead spots, a few flowers, etc.

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