common lilac

Syringa vulgaris is a large deciduous shrub or multi-stemmed small tree, growing to 6–7 metres (20–23 ft) high. It produces secondary shoots from the base or roots, with stem diameters up to 20 centimetres (8 in), which in the course of decades may produce a small clonal thicket. The branch ends may be fasciated. The bark is gray to gray-brown, smooth on young stems, longitudinally furrowed, and flaking on older stems. The leaves are simple, 4–12 cm (2–5 in) and 3–8 cm broad, light green to glaucous, oval to cordate (heart-shaped), with pinnate leaf venation, a mucronate apex, and an entire margin. They are arranged in opposite pairs or occasionally in whorls of three. The flowers have a tubular base to the corolla 6–10 mm long with an open four-lobed apex 5–8 mm across, usually lilac to mauve, occasionally white. They are arranged in dense, terminal panicles 8–18 cm (3–7 in) long. The fruit is a dry, smooth, brown capsule, 1–2 cm long, splitting in two to release the two-winged seeds.

The species is native to the southern Balkan Peninsula, where it occurs in Serbia, North Macedonia, Bulgaria and bordering regions, chiefly south of the Danube. It grows on rocky hills. Grown in spring for its scented flowers, the large shrub or small tree is widely cultivated and has been naturalized in parts of Europe, Asia, and North America. It is not regarded as an aggressive species. It is found in the wild in widely scattered sites, usually in the vicinity of past or present human habitations.

The flowers of common lilac are edible and used for flavoring honeys, sugars, food and other sweets.

The lilac is a very popular ornamental plant in gardens and parks because of its attractive, sweet-smelling flowers, which appear in early summer just before many of the roses and other summer flowers come into bloom. In late summer, lilacs can be attacked by powdery mildew, specifically Erysiphe syringae, one of the Erysiphaceae. No fall color is seen, and the seed clusters have no aesthetic appeal. Common lilac tends to flower profusely in alternate years, a habit that can be improved by deadheading the flower clusters after the color has faded and before seeds, few of which are fertile, form. At the same time, twiggy growth on shoots that have flowered more than once or twice can be cut to a strong, outward-growing side shoot. It is widely naturalised in western and northern Europe. In a sign of its complete naturalization in North America, it was selected as the state flower of the state of New Hampshire, in that state's wording because it "is symbolic of that hardy character of the men and women of the Granite State". Additional hardiness for Canadian gardens was bred for in a series of S. vulgaris hybrids by Isabella Preston, who introduced many of the later-blooming varieties. Their later-developing flower buds are better protected from late spring frosts. The Syringa × prestoniae hybrids range primarily in the pink and lavender shades.

Garden history. Lilacs—both S. …