After a long, cold winter there’s something truly glorious about the way the world finally bursts into bloom in early May. Bulbs and flower are popping up everywhere, and the world is good and green again. It’s easy to get swayed by color, but don’t forget that fragrance is one of the great joys of the spring landscape, too. And there’s no headier aroma than the classic floral scent of lilacs when they bloom in May.
Lilacs are easy to grow and ask little from gardeners once they get established. They put on strong growth and make a great hedge full of gorgeous cones of tiny blossoms in mid-spring. You can smell their scent on the breeze, and they attract nesting birds with their dense, lush growth.
Lilac Basics
Growing Zones: 3-7, though some varieties are bred for Southern zones 8-9
Bloom Time: Flowers in mid-spring; green heart-shaped leaves throughout summer
Exposure: Full sun
Mature Size: 5 to 20 feet tall and 6 to 15 feet in diameter
Notes: Lilacs for a dense, deciduous shrub with arching branches. It fills in quickly with new stems to form a hedge. Several small white or lavender flowers form lush cones in spring and perfume the air. Green leaves turn bronze and are shed in autumn.
Growing Lilacs in the Landscape
Lilacs can be planted alone as a specimen, but it’s more common to plant them in a hedge for major olfactory impact. Consider planting them in a spot where you can enjoy their fragrance on the breeze, perhaps near a kitchen window or a warm patio. Lilacs need full sun to flower, and they can spread aggressively, so it’s best not to plant them in a mixed border.
Planting Lilacs
To plant your lilac bush, dig a hole twice as wide and deep as the root ball of your plant. Lilacs don’t require highly fertile soil, but you can add some compost to the hole if you wish. Place lilac so the top of the root ball is at the surface, or plant bare root plants so the roots are covered in two to three inches of soil. Backfill your hole and press the soil firmly over the root ball. When planting a hedge, be sure to space lilacs according to the directions for the variety you chose to avoid overcrowding.
Water your plant deeply and add a layer of mulch to hold in moisture. Lilacs need regular watering in their first two to three growing seasons, and they appreciate watering at the soil level while in bloom to protect the flowers. Lilacs need about an inch of rain per week when getting established and while flowering, so supplement if it’s dry.
Ongoing Care for Lilacs
To encourage healthy growth after its first season, fertilize your lilac each spring with a general-purpose garden fertilizer, following the directions on the package for trees and shrubs. If your soil tends to be acidic, adding a bit of lime in the spring can also help keep your shrub happy.
After flowers have faded, you can deadhead them to keep the plant looking neat, though this is optional. Removing spent blooms won’t lead to more flowers as most varieties bloom just once per year, but it can direct energy into healthy plant growth. After three to five years of growth, you can prune your lilac to remove stems thicker than three inches in diameter, which don’t flower as well as younger branches.
Lilacs are one of the most care-free shrubs available and rarely have trouble with insects or diseases. If you notice powdery mildew during drought, continue to water at the roots, but know that plants usually aren’t harmed by this condition.