Lilac Love: A Guide to Spring’s Best-Loved Flowering Shrub

Almost as American as apple pie, lilacs were first cultivated in this country by the founding fathers–both Thomas Jefferson and George Washington made entries in their journals about their preferred methods of lilac care. Perhaps this is why these fragrant spring blooms have a quality of old-fashioned elegance and country romance.

Around the same time that Jefferson was busy perfecting his own lilacs, Boston merchant Benjamin Bussey planted lilac hedgerows on land that would later be donated to the Harvard University and form the foundation of what has become one of the oldest and largest collections of lilacs in North America. Today, the lilac collection at the Arnold Arboretum of Harvard University boasts more than 400 plants representing nearly 200 distinct species, making it one of the most comprehensive and famous in the world.

The height of the season is marked by Lilac Sunday at the arboretum (this year: May 12). There’s not better place to spend a delightfully fragrant morning among the impressive display, documenting the breadth and depth of the lovely lilac.

Photography by Justine Hand for Gardenista.

Above: Native to temperate parts of Europe and Asia, lilacs or Syringa are members of the olive family (Oleaceae). Here, a Syringa hyacithiflora ‘Louvais’ blooms about a week earlier than the more common Syringa vulgaris.

Above: Syringa hyacithiflora ‘Necker’ has lush, pale pink blossoms.

Above: With opulent bluish flowers, the striking Syringa vulgaris ‘President Lincoln’ was one of my favorites. (N.B.: Want your own bush? Syringa Vulgaris President Lincoln is available from White Flower Farm (ships for spring planting); for availability and price, see White Flower Farm.)

Above: As old and established as the Arnold Arboretum is, it only make sense that it would have its own cultivar. Syringa chinensis ‘Lilac Sunday’ was cultivated from a seed supplied by the Beijing Botanical Garden and named after the arboretum’s annual Lilac Sunday event, held each May since 1908.

Above: Another view of a lush Syringa chinensis ‘Lilac Sunday’. Each year Lilac Sunday entices as many as 30,000 people to the arboretum.

Above: With abundant white blooms, Syringa vulgaris ‘Frederick Law Olmsted’ was named for the famous American landscape architect who designed both Central Park in New York City and the Arnold Arboretum.

Above: Two Frederick Law Olmsted lilacs line a path that their namesake designed.

Above: Syringa pubescens ‘Hairy Lilac’ has smaller blossoms than other cultivars and downy leaves.

Above: Benjamin Bussey, the wealthy merchant who donated much of the land for the arboretum, planted the first lilacs here. (The oldest specimen still in existence is from 1897, but arboretum officials guess that Bussey planted his lilac hedgerows in 1806.) The arboretum’s gardeners have taken cuttings of the remnants of Bussey’s lilacs and recreated the hedgerows on what’s now called Bussey Hill.

Above: It was the arboretum’s first director and co-designer, Charles S. Sargent, who began predicting the best day to see the lilacs.

Above: A perfectly pruned Syringa vulagris ‘Humphrey’ looks pretty on a patch of lawn.

Above: The cut-leaf or fern-leaf Syringa protolaciniata ‘Kabul’ has leggy blooms and smaller leaves than other lilac varieties.

Above: No shrinking violet, the recently rediscovered Syringa vulgaris ‘Hulda’ displays proud, unabashedly purple blooms.

Lilac Care

• Location, location, location. Much like people, lilacs thrive in the right spot: full sun with well-drained soil. If you give them this, they are a relatively low-maintenance shrub.
• Irrigation: Water lilacs with at least 1 inch per week, but don’t drown them. They don’t like it if their roots stay wet.
• Pruning: According to the Arnold Arboretum, you should prune your lilac right after it blooms. Since flowers form in the summer, fall/winter pruning will affect the next season’s bloom. Remove all dead blossoms and cut back flowering stem to the next set of leaves. To encourage new growth in older plants, cut 1/3 of the oldest stems back to the ground for three years. Remove excess suckers.
• Fertilizer: Lilac don’t require much and, in fact, too much nitrogen can affect the bloom. A general fertilizer in the spring and again after blooming should do the trick.
• Pests: Your lilacs don’t mind the cold; keep lilacs clear of mulch in the winter, as mice and moles can find harbor under the cozy wood chips and eat the roots.
• Disease: The most common problems for lilacs are powdery mildew fungus and scale. To combat powdery mildew, The Helpful Gardener suggests a green solution of 1/2 cup milk in a gallon of water sprayed over the leaves. The resulting sour milk culture leaves no room for the mildew. (Anyone ever tried this?) For scale, prune back the most invested branches, but don’t compost. Project a hard spray on the plants to remove the “crawlers.”
• Propagation: To share the lilac love, simply dig down on any suck to expose a bit of the root and separate from the mother plant. Place in the same soil you dug it from, mixed with a little organic matter and water thoroughly.

Above: To see the lilac collection for yourself, visit the Arnold Aboretum at 125 Arborway, Boston, MA 02130.

Want to see more lilacs? Erin conjured Gatsby glamor in Glamorous Lilacs Inspired by Daisy Buchanan. Can you spot the lilacs in A Room with a View in Upstate NY on Remodelista?

Finally, get more ideas on how to successfully plant, grow, and care for lilac with our Lilac: A Field Guide to Planting, Care & Design.

Formore ideas on how to plant, grow, and care for shrubs and hedges, see our curated design guides to with our Shrubs 101.