Propagation
Stratify fresh seeds during winter and then sow in pots during spring and place in a cold frame to germinate.

Take soft tip cuttings of non-flowering shoots during late spring to early summer.
Divide the suckers during spring or in autumn.

Note:
Lilac may also be propagated from layering, root cuttings and grafted or budded onto other Lilacs or Privet rootstock.
The shrub may also be cut back hard and transplanted, requiring 2 to 3 years to recover.

Botanic information
Leaf: The dark green leaves are broad lanceolate to ovate with a pubescent underside and has an acuminate apex. The leaf margin is undulating and petiole is up to 25mm (1in) long. The sessile brownish buds have 4-pairs of scales and terminal may be absent. 

Flower: The fragrant creamy white tubulate flowers are arranged in a large, dense terminal panicle that is up to 200mm (8in) wide and appear during summer. They are a feature of the plant.

Fruit: The leathery textured beaked pea pod-shaped dehiscent capsule is green ageing to brown and contains numerous seeds. The small seeds are viable but the plant is commonly reproduced vegetatively to maintain true to type.

Pruning
Care should be taken when pruning lilacs as the flowers are produced on the previous season’s growth. Unpruned shrubs will produce many more flowers regularly and a hard prune of old plants will inhibit the flowering for up to two years until the new wood has matured. They will tolerates a light prune to bushy up immediately after flowering before the new buds are formed.