Even before the robins arrive, the first swelling buds of lilac announce the advent of spring. Soon brown branches are haloed in pale green. Then lacy clusters of flowers appear, their ruffled heads nodding and bowing in the breeze like elegant Victorian ladies, wafting perfume over fences, through alleyways and across broad, greening lawns.

Lilac is the scent of Grandmother's house, the pleasure of protected childhood, the fragrant connection with a well-loved past.

"Lilacs are the smell of spring," says Barbara Parker, owner of Home Farm Perennial Nursery in Worton, Kent County. "Once you smell the lilacs, then you've arrived."

Lilac (Syringa), a large woody shrub, was first brought to western Europe from Turkey in the mid-1500s. Thirty years ago, the common lilac (S. vulgaris, a k a French lilac) was either white, purple or classic lavender-blue. Today, thanks to hybridizers, lilacs also come in magenta, a range of pinks and purples, pale blue, creamy yellow (S. 'Primrose') and even with picotee edges like 'Sensation,' whose wine-red flowers are each outlined in white.

There are about 20 lilac species (subdivisions of the genus, or plant family) and hundreds of cultivars, which are produced artificially. They range in size from 5 to 20 feet tall, and each blooms for two to three weeks. The earliest lilacs bloom in early May, while the latest finish in late June. One exception to the spring-only blooming period is S. microphylla (little-leafed) 'Superba,' which blooms twice each season -- in May and again in August.

Lilacs are cold-climate plants. "This is sort of a marginal area for lilacs," notes Jane Baldwin, president of the Arboretum Association of Cylburn Manor Gardens in Baltimore. An exception is 'Blue Skies,' which grows well even in warmer climates. Most lilacs are single-flowered, with four petals at the end of tiny blossoms that are grouped in beautiful, pyramid-shaped clusters called panicles. But several lilacs bear double-flowered panicles, their blooms a mass of tiny, fragrant crinolines.

Alan Summers of Carroll Gardens in Westminster says that while the ruffled, double-flowered lilacs are great for cutting, he doesn't like them for landscaping.

"The flower heads are floppy," he says, "although a couple of double-flowered Russian hybrids, 'Beauty of Moscow' ('Krasavitsa Moskvy') and 'Hope' ('Nadezhda'), are stronger-stemmed than the others."

Summers prefers the compact dwarf Korean (S. meyeri) lilacs. "They're much easier to use in the landscape," he says. "You can plant them close to the house. Things like 'Palibin' or 'Superba' and 'Miss Kim' are very good and have very fragrant blooms."

Additionally, each are resistant to powdery mildew, a blight that covers the leaves of common lilac with an unsightly gray haze.

Thanks to early, mid-season and late lilac cultivars, gardeners can extend bloom and fragrance for six to eight weeks in spring.

Hyacinthifloras (S. x hyacinthiflora) bloom first, followed in roughly a week by the common lilacs. The Dwarf Korean lilacs bloom about a week later, followed closely by Canadian lilacs (X prestoniae), which butterflies love. The Japanese tree lilac (S. reticulata) and Chinese tree lilac (S. pekinensis) are the last to bloom in late spring and early summer. Slightly larger than a dogwood and covered with white panicles, the Japanese tree lilac is tolerant of neglect.

"There's one in front of an apartment building I go by that doesn't get any care," Summers says. "But its beauty is beyond belief, and the fragrance in June! You can smell it all up and down the block!"

Lilacs thrive in full sun. When planting, add a little compost and, if the ground is slightly acid, add a little bonemeal or crushed egg shells to the hole. A new lilac may take two years to bloom. Because spring bloomers flower on last year's growth, prune right after bloom.

"Prune between one-quarter to one-third of the largest and oldest branches each year," advises Baldwin. It not only shapes but lets light and air inside, and that reduces mildew.

Sources

* Carroll Gardens, 444 E. Main St., Westminster, Md. 21157; 800-638-6334

* Wayside Gardens, 1 Garden Lane, Hodges, S.C. 29695-0001; 800-845-1124; www.waysidegardens.com

* Cylburn Arboretum Association, 4915 Greenspring Ave., Baltimore, Md. 212??; 410-367-2217

Buying smart

When buying a lilac, Alan Summers of Carroll Gardens in Westminster offers several suggestions:

* Make sure the root stock is lilac so that when it suckers, (sprouts a new shoot from the roots), it grows a lilac. (Lilac shoot is sometimes grafted onto privet root for economy.)

* Check the ultimate height and breadth.

* Consider a potted lilac rather than bare root, because bare root lilacs re-establish slowly.

* If cost is an issue, get a potted lilac one size smaller than you want, rather than a cheaper, larger, bare root lilac plant. A small one will get bigger, but a larger, poor one will never get better.

Lilacs at a glance

Lilacs are cold-hardy from climate zones 7 north to zone 2 in Canada and offer a big return for a small investment in time and effort. All they need is full sun, well-drained soil with nearly neutral to slightly alkaline pH, and some pruning to keep them going for a years and years.

Cut dead wood to the ground and clip down over-tall branches annually. Dwarf Korean lilacs and Canadian lilacs resist powdery mildew, a leaf blight that looks bad but doesn't harm the plant.

Pub Date: 03/21/99