The lilacs opened in my garden this morning, and as the breeze carried that heady scent through the open window for the first time this year, I was instantly transported back to my childhood in Milwaukee, walking with my mother to school on sunny May mornings past towering shrubs of redolent lilacs. Long forgotten details – the feel of my mother’s hand as she guided me across the busy street, the starched crinkle of her skirt as we walked, even the tiny yellow chamomiles that somehow managed to grow and blossom in the cracks of the sidewalks over which we passed – all these memories and more came flooding back thanks to the shrub which has been aptly named the “mother of memory.” Given this magical power, it’s no wonder that people are passionate about lilacs as they are about no other shrub– in their hundreds of forms they are now ubiquitous in American and European landscapes. In fact, they are so extensively cultivated that somehow I had always presumed that lilacs had graced Western gardens as long as there had been gardeners. As it happens though, the memory of lilacs in the West is a surprisingly short one: in less than 400 years, the lilac has risen from almost complete obscurity to become the crowning shrub of the spring garden.
The lovely lilac is a member of the Oleaceae family, which includes privets and olives, and is divided into two main groups – the vulgares, which bloom on the previous years wood, and the villosae, which bloom later in the season on new growth. It was a member of the former that was first noticed growing in Turkish gardens by the Austrian ambassador to court of Suleiman the Magnificent, Ogier Ghiselin de Busbecq. A collector of anything curious and new, this still famous plantsman brought a specimen of S. vulgaris (the common lilac) home with him to Vienna in 1562, and within just a few years the plant had been spread among the horticultural cognoscenti of Europe. The great herbalist Gerard notes that he had lilacs growing “in very great plenty” in 1597, and by the early 1600’s, the common lilac had lived up to its name. So popular was the plant that it became naturalized throughout much of Britain and the Continent, (and very shortly afterward, in the temperate regions of North America as well.) While it was generally remembered that the plant had come “from the Orient”, no one could identify with any certainty its actual place of origin. Its wasn’t until 1828, when naturalist Anton Rocher found truly wild specimens in Balkans, that its native home was discovered.
Several other species, (such as the Persian lilac, S. persica, brought back by the Venetian ambassador from Constantinople) were soon added to the western gardening palette, but for most of the 17th, 18th and 19th centuries, the number of lilacs in cultivation remained strangely small, either due to general contentment with the lovely types already at hand, or because there were not a sufficient number of potential parent species to produce new varieties. Then fate took a hand. In 1870, during the Franco-Prussian war, the Germans overran the northern portion of France, including the town of Nancy, home to the famous nursery of Victor Lemoine et Fils. According to the story, M. Lemoine, with his trade pretty much idled for the duration, had decided to pass his time trying to breed a good double lilac. M. Lemoine however, had very poor eyesight, a true disability for anyone interested in pollinating the tiny individual flowers of the lilac, and so it fell to poor Madame Lemoine to stand for hours on a ladder, petticoats fluttering in the wind, gently pollinating selected shrubs. Fortunately for us she persevered, and between 1876 and 1927, the firm introduced over 153 named cultivars, many of which remain garden favorites to this day. (see below) This and subsequent breeding programs, combined with the introduction of new species from China around the turn of the century, means that today’s selection of lilacs now numbers well over 500.
Given the lilac’s terrific popularity, its no wonder that I am probably asked more questions about the this shrub than any other. The majority are variations of “I bought a lilac several years ago and it has never bloomed. Why?” and with very few exceptions, the answer is generally the same: the lack of bloom is the result of either insufficient light or inadequate soil. Lilacs require full sun to flower well. This means a minimum of at least 7 hours of uninterrupted sun each day: anything less will result at worst in just leaves, and at best, a tall scraggly shrub, with a few blooms on top, stretching for the light. Another common problem is soil pH. Lilacs prefer slightly alkaline soil, and I have found that the shrubs do best when planted with a handful or so of pelletized lime, with an occasional re-application every year or so, especially if your soil naturally runs towards the acidic. For those of you with wood burning stoves or fireplaces, this is the ideal occasion to use those ashes, which not only supply essential potash, but also raise pH. Other than these two issues, lilacs are generally untroubled, although lilac scale and certain mildews can sometimes be a problem if left unchecked. Lilacs are extremely resilient, hardy (many to Zone 2) and long-lived: In fact, sociologists have been using lilacs for years to track migration patterns westward across our continent. Long after the house and garden have disappeared, the resilient lilac often lingers, the last testimony of a once-flourishing homestead.
Another commonly asked question has to do with pruning. While overgrown lilacs can easily be regenerated by removing a third of the old growth each year until vigorous new suckers take over, in general, its best to follow my grandfather’s advice for lilacs – “Pruning sheers and lilacs make unwelcome companions.” My grandfather was particularly vigilant when it came to his prized bushes of S. vulgaris – woe be to anyone who even attempted to move towards them with anything resembling a blade, especially interlopers intent on cut flowers. This of course has to do with most lilac’s habit of blooming on old wood: prune anytime before flowering and you cut off this year’s bloom, anytime after, and you weaken next year’s. “Lilacs,” Grandpa used to say, “thrive on benign neglect and are best appreciated on the bush.” While these days I almost invariably follow my grandfather’s teachings, this is one dictum that I violate regularly, and if truth be told, with a certain glee. While no lilac makes a great cut flower (the blossoms, depending on variety, wilt within a day or two) there are few experiences more heavenly than walking into a room filled with lilacs. Somehow the fragrance is only enhanced by its ephemeral nature.
My solution to not having to worry about next year’s bloom is simply to plant as many lilac bushes as possible. That way you can easily shrug off a few fewer blossoms on any one particular shrub. This also gives you an excuse to experiment with a number of different varieties: properly planned, the lilac season can be extended well over a month, beginning with some of the earliest varieties like S. oblata, the Early Lilac, and ending five or six weeks later with S. reticulata, the Japanese tree lilac. Over 20 varieties now bloom in my own garden, with several more added each year. Eventually I suppose, I shall run out of room and be forced to stop, but for now the possilbility of having a plethora of lilacs seems a fate almost too delightful to contemplate.
This question of space can rapidly become an issue for even the most expansive garden, as lilacs are indeed large shrubs, many growing to 30 feet high and 15 feet wide. Thus I am often asked by novice gardeners with room for only one or two plants which variety they should choose, and my advice invariably is the one you like the best. There are hundreds of variations in form, flower and habit to choose from, including wide differences in scent. This last is something that I had not paid much attention to until a visit with my mother to Boerner Botanical Gardens in Milwaukee several years ago. The gardens there have an extensive collection of lilacs, and we spent several ethereal hours wandering the grounds, paying attention not only to the various flower colors, the presumed purpose of my visit, but also enthralled by the wide range of fragrances. The differences turned out to be truly amazing: from light fruity scents with only a hint of lilac, to heavy musky perfumes so heady as to be almost intoxicating. There were even some unfortunates, who despite their gorgeous blooms, seemed to have very little fragrance at all, which to me at least would obviate the lilac’s entire reason for being. So before you decide, be sure to visit a nursery or show garden at lilac time to find your favorite. And get your checkbook ready: Given the lilac’s magical allure, it’s doubtful you’ll be coming home alone.