Lilac – Plant Profile

Syringa vulgaris

Purple flowers about to bloom on a Miss Kim lilac bush.

“Miss Kim” lilac about to bloom.

Common Varieties: “Miss Kim”, “Lincoln”, “Mme. Lemoine”, “Miss Canada”, Dwarf Korean, Persian Lilac

Description: Lilacs are a type of deciduous, flowering plant that’s generally a shrub, but some varieties can become trees. They’re famous for their fragrant clusters of flowers that appear in late May. Lilac is a multi-stem, woody shrub covered in broad, bright green leaves.

Lilac flowers come in so many shades, ranging from white to dark purple, and even a couple pink varieties.

A close up detail of pale purple flowers on an "Old Fashioned" lilac bush.

Detail of “Old Fashioned” lilac flowers.

A Historic Flower: The lilac bush has a long history. The shrub originated in Asia, where we still get common varieties like Chinese, Japanese, Persian, and Dwarf Korean lilacs. After coming to the Europe via the Ottoman empire, it was transplanted by 1500’s gardeners across the continent. It came to the United States in the mid-1700’s, even becoming part of the gardens of George Washington and Thomas Jefferson! The longest living lilac bushes in the United States can be found at the Governor Wentworth Estate in Portsmouth, NH – where they were planted around 1750.

Planting and Growth Habit: As a rule, lilacs prefer full sun areas, so make sure you place them where they’ll get about 6 hours a day. They also prefer well drained, neutral soil. When planting, incorporate some compost into the soil to give it a good start. It’s a good idea to put down a layer of compost each spring as well, and apply a small amount of granular fertilizer early in the spring.

Lilacs tends to bloom profusely on alternating years. To encourage more and longer lasting flowering periods, remove spend flower heads to the shoot. Other than that, lilacs need little pruning. Remove leggy shoots when they appear to keep the plant looking tidy. Prune after bloom period, before the hot weather sets in around July.

Lilacs generally grow to about 5′ on average, with a lot of variation between species. Two of our favorites, “Miss Kim” and the Korean Dwarf Lilac, are compact varieties with a low, mounding tendency – about 3′-5′ in height. “Old Fashioned” lilac is a more classic style of shrub, growing to about 7′-9′.

Special Features: Hardy, low maintenance, fragrant, deer-resistant, full sun, fast growing.

Design Tips: Some varieties of lilac make a great low hedge, like Dwarf Korean lilac. Others are better in a shrub border, especially paired with evergreens that make those purple flowers pop.