Lilac
Syringa vulgaris
Lilac blooms from April through May.
Mature size, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not.
Growing Lilac
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 3–7. Expect it to reach about 9.8 ft tall and 8.2 ft wide at maturity, in roughly 4 years.
When to plant Lilac
Plant Lilac in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. For the middle of its hardy zones 3 to 7 range, spring means April to June and fall means August or September. Once settled, it blooms from April to May.
Month-by-month timing for your zone is on the planting calendar: for the middle of its range, start with zone 5 in April.
Comes in 13 varieties across 5 colors
Same plant, same care - pick the color you are growing.
Good to know about Lilac
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Worth knowing
Full sun fixes two problems at once: shade that starves bloom also raises humidity and drives powdery mildew, so a sunny, open spot means more flowers, less disease. per NC State and Iowa State
Renewing an overgrown lilac
To renew an old lilac, remove a third of the oldest stems yearly over three years and keep bloom, or cut it low and lose three years of flowers. per Nebraska and Minnesota
Prune right after flowering
Lilac blooms on old wood and sets next year's buds the summer after it flowers, so prune right after bloom; a later cut removes next year's flowers. per NC State and Penn State
Needs a cold winter
Common lilac needs a long winter chill for its flower buds to mature, so it blooms poorly in the deep South and other mild-winter regions. per NC State and Minnesota
Safe, but mind the name
True lilac (Syringa vulgaris) is generally non-toxic to pets and people. Do not confuse it with 'Persian lilac' or chinaberry (Melia azedarach), an unrelated, genuinely poisonous plant. per Extension Horses and NC State
It suckers from the roots
Lilac suckers from the roots and can slowly form a thicket. Most plants are grafted, so remove rootstock suckers, or you get a different plant than the named top. per NC State and Minnesota
What pairs well with Lilac
Good companions share its growing conditions and add something it lacks: an earlier or later bloom, a lower carpet in front, or structure through winter.
Aster
Shares full sun and moderate water; blooms in early fall, extending the bed's season; both offer pollinator forage, in different months; its seed heads stand through winter, for structure and the birds.
Lavender
Shares full sun and low to moderate water; blooms in early summer as this one finishes; both offer pollinator forage, in different months; evergreen, so the bed keeps its shape through winter.
Blazing Star
Shares full sun and low to moderate water; blooms in midsummer, extending the bed's season; both offer pollinator forage, in different months; its seed heads stand through winter, for structure and the birds.
Black-Eyed Susan
Shares full sun and low to moderate water; blooms in midsummer, extending the bed's season; both offer pollinator forage, in different months; its seed heads stand through winter, for structure and the birds.
Trumpet Vine
Shares full sun and moderate water; blooms in early summer as this one finishes; both offer pollinator forage, in different months; climbs to 26 ft behind it, height without the footprint.
Fan Flower
Shares full sun and moderate water; overlaps, then carries the display into mid fall; low at 8 in, to carpet the ground beneath; blue sits close to purple on the wheel.
Verbena
Shares full sun and moderate water; overlaps, then carries the display into mid fall; low at 10 in, to carpet the ground beneath; echoes the purple.
Lobelia
Takes full sun to part sun and moderate water; overlaps, then carries the display into early fall; low at 8 in, to carpet the ground beneath; both offer pollinator forage.
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