
Lilacs
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. Learn how to take care of lilacs as well as prune at the right time.
ABOUT LILACS
The common lilac, Syringa vulgaris, blooms in the northern states for 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.
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.
PLANTING
- Lilacs thrive 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.
- For strong bloom, lilacs require full sun—at least 6 hours—or they will not flower 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 their 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, 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. Water in. Then fill in the hole with more topsoil.
- Space multiple lilac bushes 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/DISEASES
- 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.
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.
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 shall mourn with ever-returning spring.” - Lilacs supposedly symbolize the joy of youth.
You may also like
This site uses Akismet to reduce spam. Learn how your comment data is processed.
Archives
- June 2025
- May 2025
- April 2025
- March 2025
- February 2025
- January 2025
- December 2024
- November 2024
- October 2024
- September 2024
- August 2024
- July 2024
- June 2024
- May 2024
- April 2024
- March 2024
- February 2024
- January 2024
- December 2023
- November 2023
- October 2023
- September 2023
- August 2023
- July 2023
- June 2023
- May 2023
- April 2023
- March 2023
- February 2023
- January 2023
- December 2022
- November 2022
- October 2022
- September 2022
- August 2022
- July 2022
- June 2022
- May 2022
- April 2022
- March 2022
- February 2022
- January 2022
- December 2021
- November 2021
- October 2021
- September 2021
- August 2021
- July 2021
- June 2021
- May 2021
- April 2021
- March 2021
- February 2021
- January 2021
- December 2020
- November 2020
- October 2020
- September 2020
- August 2020
- July 2020
- June 2020
- May 2020
- April 2020
- March 2020
- February 2020
- January 2020
- December 2019
- November 2019
- October 2019
- September 2019
Leave a Reply