Pruning Lilacs

Lilacs have been garden favourites for 300 years. This simple guide will help you care for your fragrant lilacs.

A gardener’s advice

Lilacs demand neutral, well-drained soil. If your site is wet, plant them in a mound so that surface water will drain off. They also need 5 hours of sun daily and an occasional dose of lime to keep the soil neutral to slightly alkaline.

Remember: be patient! Young lilacs need a few years to establish and produce maximum blooms.

Painless deadheading
  • Clip plenty of bouquets for indoor arrangement–it will lessen deadheading chores and you’ll have fragrant flower clusters to scent the house.
  • Smash the woody stem ends with a hammer; this will help cut lilacs take up more water.
  • Lilacs bloom on the previous year’s wood, so also cut back the plants after blossoming ends to stimulate new growth.
Rejuvenate overgrown lilacs
  • To rejuvenate an overgrown lilac, either cut the whole plant back to the ground or remove a third of the oldest stems each year over 3 years to promote new sprouts from the base. Conscientious annual pruning makes drastic measures unnecessary.
Watch out for mildew
  • Lilacs are prone to powdery mildew, which covers foliage with white fuzz in late summer. Prevent the problem by pruning to promote air circulation.
  • Also keep shrubs away from walls and reduce stress by watering and fertilising regularly.