Few plants evoke nostalgia and fond memories more than the common lilac and gardeners from cold climates that move to warm areas pine over the loss of the common lilac. Although their bloom time is short the heavy trusses of flowers with their fabulous fragrance are always a favorite in either the garden or bouquets. The fragrance of these lilacs is one of the great miracles of nature and those who have never smelled it can never understand the sentiments of those of us who extol its virtues. But lilacs offer more than just fragrance; they also have full, billowing terminal clusters of flowers that spell old-fashioned romance even if they were not fragrant. The dark green heart-shaped leaves borne on the upper part of the bush are attractive in spring and summer (but do not produce good fall coloration.) Lilacs are effective used as specimen plants, in small groups, and as part of a shrub border. Bees, butterflies and birds find them attractive too.
Type: Deciduous shrub.
Outstanding Feature: Fragrant trusses of flowers in late spring.
Growth Rate: Moderate.
Bloom: Lavender, white, blue, magenta, pink purple and purple edged with white in spring; a yellow cultivar (‘Primrose’) usually appears as cream in the US; some cultivars have double flowers.
Size: 8’-15’H x 6’- 15’W.
Light: Full sun.
Soil: Prefers rich, moist, well-drained, neutral soil; will not tolerate wet feet. In times of drought water deeply as lilacs have deep roots.
Fertilizer: Use a general fertilizer or one high in phosphorous before bloom to promote flowering. Fertilize again after blooming.
Hardiness: Zones 3-6. Plants will grow in 7 and warmer but do not reliably bloom well. Southern gardeners should consider ‘Lavender Lady’ that blooms with little winter chill or other kinds of lilac such as Syringa patula ‘Miss Kim’, smaller than the S. vulgaris, or the dwarf Korean lilac, Syringa meyeri ‘Palibin’, mauve-pink, 5’ H, with spicy fragrance..
Care: Many lilacs tend to bloom profusely in alternate years, but prompt removal of flowers will improve next year’s flower production; prune soon after flowering (lilacs flower on old wood).
Pests and Diseases: Can suffer from aphids, powdery mildew and scale.
Propagation: Cuttings and seed; transplants easily
Companion plants: Since bushes may get leggy and provide little interest in the garden after flowering they should be placed at the back of the border where other plants can be placed in front of them. Tulips, daffodils, and other bulbs that flower at the same time as the lilac are attractive companions.
‘Dappled Dawn’ (also known as ‘Acubifolia Variegata’) Yellow variegated leaves, blue-purple flowrs
‘Katherine Havemeyer’ – classic pink; 12’ H, resists mildew.
‘Ludwig Spaet’: A very old form, reddish purple flowers, 12’ H.
‘Lavendar Lady’: Lavender flowers; best for warm climates.
‘Miss Ellen Willmott’ : Double whites flower, rounded form, 10’ H. ‘Sensation’: purple flowers edged with white; 10’ H.
Comment: Lilacs take a year or two to get established and will not bloom the first year. Once they are established they are very long lived.