Syringa vulgaris
shrubZones 3–7Old-fashioned fragrant shrub with pyramidal flower clusters in spring. Intensely sweet fragrance beloved for cut flowers. Extremely cold-hardy and long-lived.
Remove spent flower heads and thin oldest stems to the ground. Lilacs bloom on old wood so prune within 2 weeks of bloom ending.
Pull or cut root suckers growing away from the main clump to control spread.
Lilacs are very susceptible to powdery mildew in humid weather. Mostly cosmetic but unsightly.
Flower buds for next spring are already set. Any pruning now removes next year's blooms.
Lawn Guardian turns this guidance into a schedule timed to your USDA zone and this week's actual weather — and adapts every time you log what you've done.
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