A small family of medium to large hardy deciduous shrubs or small trees, with spectacular colourful spring flower trusses. Although the flowering season is fairly short, it is still a very popular and easily grown garden favourite.
Family: Oleaceae (olive family)
Botanical Name: Syringa
Common Names: Lilac
Foliage: Deciduous, heart-shaped, mid-green leaves.
Flowers: Large conical panicles of small, tubular flowers. highly scented. In shades of lilac, pink and white.
Flowering Period: Most varieties flower around April or May.
Soil: Any moist but well-drained soil (chalk, clay, sand or loam). Alkaline or neutral pH.
Conditions: Full sun or partial shade. Best grown in a south, east or west-facing aspect, in a sheltered location.
Type: Large shrub or small tree.
Origin: Europe and Asia.
Hardiness: Hardy in most regions of the UK.
Plant outside in early autumn. Container grown plants can be planted out at any reasonable time of year.
Grow in an open sunny position in any good, well drained, fertile garden soil. They prefer a deep and fertile loam that is slightly alkaline. Remove the flower buds in the first year to improve vigour.
Makes a good specimen tree, border shrub or a hedge. An excellent shrub for chalky soils.
Water thoroughly during dry weather until well established. Mulch with organic matter in spring and apply a general fertilizer suitable for shrubs.
Dead head (at least when young) and cut out any old or weak wood after flowering.
Can be regenerated by cutting back hard in winter or early spring.
Remove rooted suckers, especially from grafted plants.
Susceptible to attack by caterpillars, lilac leaf miner and thrips.
Usually very robust if growing conditions are good but it can be affected by a wide variety of diseased such as fungal leaf spot, honey fungus, lilac blight and silver leaf.
Seed can be sown outdoors in spring, although cultivars will not come true to type.
Strike softwood cuttings in late spring or pot-up rooted runners. Can also be propagate by heel cuttings in summer.
A good selection of lilac species and varieties are available for the garden, from tall shrubs to more compact and even dwarf forms.
Syringa vulgaris (common lilac) a large deciduous shrub or small tree that produces highly fragrant flower clusters in April. Height to 12ft (3.6m) or more, spread to 10ft (3m). A wide range of single and double cultivars are available, in shades of lilac, mauve, red, pink and white.
Syringa x hyacinthiflora (Early Flowering Lilac) is a large cultivar that flowers earlier than normal.
Syringa meyeri 'Palibin' (Korean Lilac) is a slow-growing, deciduous, bushy shrub with fragrant lilac flowers in late spring. Suitable for smaller gardens or pots and containers. Height and spread to 5ft (1.5m).
Syringa microphylla is a compact form with small leaves and open flower clusters. Height and spread to 6ft (2m) high and wide. One of the best cultivars is 'Superba', which produces fragrant pink or white flowers from June to October.
Syringa x prestoniae is large hardy hybrid, bearing large upright panicles of lilac pink or white flowers in late May-June. Height to l3ft (4m), spread to 10ft (3m). A number of good named cultivars are available.
Syringa x josiflexa 'Bellicent' is a tall hybrid with fragrant pink flowers in slim clusters. Flower a few weeks later than normal. Height to 15ft (4.5m), spread to 12ft (3.6m).
Syringa x chinensis (Chinese lilac) is a hybrid that produces attractive purplish flowers in late spring. Ideal for a hedge or screen. Height to 10ft (3m). A number of good named cultivars are available.
Syringa pubescens (native to Korea and China) is a large deciduous shrub with green leaves felted white underneath and heavily scented lilac flowers in early summer. Height and spread to 20ft (6m).
Syringa velutina a dwarf form that makes a small rounded bush, with lavender-pink flowers in May. Height to 4ft (1.2m). Another Korean lilac. May be difficult to find in UK nurseries.