How to Grow and Care for Lilacs

With dozens of species, cultivars, and hybrid varieties, there's a lilac shrub in a color and size to suit any yard. Once established, these plants are drought-tolerant and low-maintenance, while their cold hardiness allows them to thrive even where winter temperatures drop below zero.

"Lilacs provide some of the earliest forage material for pollinators and emit a beautiful fragrance," says Cecilia de Corral, the director of design and build at Brooklyn Grange Rooftop Farm. "Despite only providing blooms for a short-lived period, their fragrance and structure makes the space they'll take up in your garden well worth it."

As rewarding as growing lilacs at home can be, getting a bountiful profusion of aromatic blooms requires the right location, sun, soil, and pruning practices.

Lilac Varieties

The original common lilac grew in shrubby groups on the cliffsides of the Balkan peninsula, but their iconic fragrance soon made them—and their cultivars—a garden staple, says Vince Marrocco, the Gayle E. Maloney director of horticulture at Morris Arboretum & Gardens of the University of Pennsylvania.

"The real explosion of lilacs as a staple of the horticultural world came about in the late 1800s and almost all at the hand of one man: the French plant breeder Victor Lemoine," says Marrocco. "His obsession with lilac breeding lead to the introduction of over 200 cultivars, and the term 'French lilacs' to describe his many creations."

Lemoine's contributions include President Grevy, Charles Joly, and Monge lilacs. In the early part of the 20th century, Isabella Preston of the Ottawa Experimental Farm bred lilacs designed to bloom later in the season; the Preston lilac hybrid taxa was named for her, says Marrocco. More recent additions to the lilac family include the repeat-blooming Bloomerang and the compact, cold-hardy Fairy Tale series.

Other popular varieties of lilacs include the Miss Kim, the common lilac, and the Dwarf Korean lilac, among others.

Common Lilacs

Arguably the most popular lilac variety, these shrubs are beloved for their colorful and fragrant flowers. "The flowers are typically purple to lilac, but some cultivars can be magenta, pink, or white," says Heather Trilling of Trilling Landscape Design & Build.

Dwarf Korean Lilac

If you aren't working with a ton of square footage in your garden, then this is the lilac for you. "The Dwarf Korean Lilac is great for smaller spaces because of its size," says de Corral. "It typically doesn't exceed six feet in height, so it's a wonderful option for a lower hedge or as an accompanying shrub to a perennial landscape. It is also tolerant of urban conditions and can thrive in containers with appropriate drainage and light."

Miss Kim Lilac

Garden expert Melinda Meyers says Manchurian lilacs, including Miss Kim, are highly sought after because of their eye-catching, aromatic flowers. "The flowers can be any color from icy blue and burgundy to lavender-pink and the plants can grow up to seven feet tall," she says. "Fall planting is preferred, as the soil is warm and the air is cool, thereby reducing transplant shock, and major pruning should be done in late winter."

The Miss Kim is also one of Marrocco's favorites. He describes it as "nearly bulletproof. Disease resistant, incredibly fragrant, low-maintenance, and drought-resistant (once established)."

Early Lilac

The earliest bloomer at the Morris Arboretum is Syringa oblata, which begins flowering as soon as March. "It's fabulous for early color and fragrance and is shown to best effect in the back of the border, where it calls attention to itself in the early season, and then can fade into obscurity for the remainder of the year," says Marrocco.

Persian Lilac

A spreading, graceful shrub with arching branches, the Persian lilac is the perfect plant to use for the borders of your yard, says Trilling, because their blooms attract butterflies and hummingbirds. "The leaves are dark green and pale pink flowers appear in spring and are very fragrant," she says.

Chinese Lilac

A hybrid of common and Persian lilacs, Chinese lilacs are known for their long-lasting dark purple blooms, says de Corral. "Its wide spreading branches make it a great option for cut flowers, and it's more resistant to powdery mildew than other varieties," she says.

How to Care for Lilacs

Once established, lilacs are low-maintenance garden staples—but for the first few growing seasons, they may need more attention.

Sunlight

For the best bloom results on your lilacs, plant the bushes in full sun. Though the plants will survive in shade or part sun spots, you'll spot the difference; they won't flower as well. "Like most flowering shrubs, more sun equals more flowering," says Marrocco.

Soil

Plant your lilac in rich, moist, well-drained soil. A new plant prefers soil with a neutral pH of 6 to 7, while more established plants can handle a slightly alkaline soil. "In general, they're pretty amenable to soil types," says Marrocco. "However, they don’t like wet feet, so good drainage is important."

Watering

While more mature lilacs are hardy with little water, it's important to keep the plants well-watered in their youth. "In the wild, they can grow on cliff faces, so they're also pretty tolerant of droughty conditions once established," says Marrocco. "The 'once established' part is the thing some folks gloss over. You can't expect them to survive if they haven't had a chance to establish a root system!"

Expect to water lilacs deeply once or twice a week (when the top inch of soil is dry) for the first two to three years after you plant it. Once established, you can water only during lengthy dry spells.

Fertilizer

Lilacs typically don't need fertilizer, but adding a balanced 10-10-10 product in early spring can help support its blooming abilities. "We don't generally fertilize our lilacs, but a light fertilization with a low dose organic fertilizer would always be a good thing," says Marrocco.

How to Prune Lilacs

Prune out dead or broken stems each year to improve the overall look of your lilac, and cut back stems to maintain your desired plant size. Deadheading and trimming should happen right after the flowers bloom.

"In general, lilacs bloom on old wood, so pruning immediately after flowering is best to maximize the floral display for the coming season," says Marrocco. "Late season pruning or early spring season pruning may be required, but do so with the knowledge that you're also pruning off the coming season's blossoms."

How to Transplant Lilacs

Transplanting a young lilac is easier than accommodating the movement of an older one, since the bushes can grow up to 15 feet tall and 12 feet wide, with a root ball about 50 percent wider than the width of the shrub.

Plan to move the shrub during its dormant period in late winter, before leaves and buds appear. When transplanting, dig a hole that's about twice as big as the root ball, and ensure none of the root ball sticks out above the top of the soil. Water deeply and regularly to allow the roots to establish themselves in the new spot.

How to Care for Lilacs in the Winter

Hardy lilacs can thrive in even the coldest parts of the United States, withstanding winter temperatures that drop to -60 degrees Fahrenheit. They require a cold dormancy period to survive, and need little to no assistance to survive the winter. Add mulch to ensure the roots remain covered during the winter, and consider wrapping the plant to protect delicate buds from an early spring freeze.

How to Care for Lilacs in Containers

Smaller, dwarf lilacs can grow in containers, though you need a large pot—at least 2 feet in diameter—to make sure that the roots remain completely covered. Since lilacs require a dormant cold period to bloom, leave the lilacs outside during the winter, burying them for insulation if you live in an especially cold climate.

Common Problems With Lilacs

Lilacs can be prone to developing powdery mildew, says Marrocco—especially when planted in small areas where the leaves may remain damp. "These are plants whose parents inhabit wind-swept Balkan cliffsides," he says. "Powdery mildew is most prevalent when plants are in enclosed gardens or where water sits on the leaves for a long time after rain or irrigation. The best way to combat this disease is to plant common lilacs and French lilacs in open locations and prune them to have a more open habit."

The lilac borer insect, a clear-wing moth that looks like a paper wasp, damages the plant by tunneling into the wood (it also infests ash trees). Insecticides that attack lilac borers should be applied during the period when eggs are laid and hatching, from spring into early summer.