Lilacs

Lilacs belong in the genus Syringa, a word that means “tube”. This refers to the shape of the blossoms, and is also where the word “syringe” comes from. They belong in the olive family (Oleaceae), and they are most closely related to olives, ash, privet, jasmine, and forsythia. There are about 25 species, all from cold parts of Asia and Europe. In the wild, they grow on the edges of woodlands and sometimes high in the mountains, always growing in sunny places with good drainage.

Lilacs are generally considered large shrubs and the average size is about 10 or 12 ft. tall and wide. They require full sun, and fertile (but not overly rich) soil. They appreciate moisture but they are extremely drought resistant, and they have no known pest or disease problems. Powdery mildew can be an issue under very wet, cold growing conditions but this is unusual for most varieties, except for the "twice flowering" types. Lilacs reliably set flowers once per year, but certain varieties have been bred to flower more freuquently and the trade off is that they tend to be less healthy overall.

Lilacs are extremely hardy and very adaptable; they can grow in shade but they will absolutely refuse to flower. The French lilacs often have a suckering habit, but that’s it as far as possible issues are concerned. Lilacs in general are intolerant of flooding. They flower profusely and exuberantly, they are gorgeous and fragrant, and the flowers are a major nectar source for bees, butterflies, hummingbirds, and sphinx moths. You have every reason to add them to your garden.

The flowers of most lilacs range from purple to violet to mauve in color, but there are lots of variations. They flower best if left unpruned or pruned immediately after flowring (blooms are produced on previous year's wood wood).

Very elderly lilacs develop spectacularly twisted, almost spiraling trunks that can be incredibly beautiful. They can live for over 100 years, and their very dense, beautiful wood is occasionally used by carvers and woodworkers, most often to make either musical instruments or knife handles. 

Lilacs are considered moderate to fast growing, and will flower well even from a young age.  They are especially popular for parks and schools, and there are many places (especially in North America) that hold annual lilac festivals. The largest collection of lilacs in the world is in the Royal Botanic Gardens of Hamilton, Ontario. It holds nearly every known species and over 300 different cultivars.

Most of the lilacs we grow are hybrids, but a few of the species are grown.

Syringa josikaea is sometimes called the Hungarian lilac, and can occasionally be found in gardens.

Syringa meyeri is the dwarf Korean lilac, which is also called the little-leaf lilac. It usually grows about 5 ft. tall and just as wide, but occasionally it can be as much as 8 ft. tall and wide. It is a profuse bloomer and has small, elegant violet blooms in great profusion. It has been much used in breeding programs for new lilacs because it is reasonably small and compact.

The Japanese tree lilac (Syringa reticulata) is the largest species, usually growing around 18-20 ft. but occasionally it can be as tall as 40 ft. Since it is the only true tree form of lilac, we've included it under a different entry.

Syringa villosa has pinkish flowers and has been much used for shelterbelts and windbreaks, and it’s the only lilac that reliably self seeds here.

The most important species, the common lilac (Syringa vulgaris), is the one that has been most extensively used in the hybridization and development of new cultivars.

The common lilac and some of its naturally occurring hybrids were first introduced to European gardens at the end of the 16^th century. These were sometimes called “Persian lilacs”. They were first grown in America in the 1800’s by famed Pennsylvania gardener John Bartram, who is believed to have grown them from seed.

Lilacs can be grown from seed, but they are usually propagated either by cuttings or grafting. Hybrids do not breed true from seed, and seed to bloom can take over 10 years. Most of the hybrids do not produce fertile seed, but will flower more consistently if spent blooms are removed. The first person to take a serious interest in breeding new lilacs was the extraordinary nursery man Victor Lemoine (1823-1911) of Nancy, France. In his lifetime, he bred and introduced nearly 200 new cultivars, and vastly increased the available color range of lilacs. Not only are most of his cultivars still available, they are often the standard by which new lilacs are still judged. French lilacs are known for their heart-shaped leaves, huge clusters of extremely fragrant flowers, and tendency to sucker if their roots are disturbed. Lemoine was also the first person to introduce double flowered cultivars, and he was the first foreigner to receive the Royal Horticultural Society’s Victoria Medal, the highest honor that can be awarded. Even today, new lilacs that are introduced with parentage from Lemoine’s plants are referred to as “French” lilacs. 

Victor Lemoine, however, was by no means the only lilac breeder of note. One of my greatest gardening heroes is the remarkable Isabella Preston (1881-1964). Although she was born in England, Isabella Preston came to Canada in 1912 and not only stayed and made a life for herself, her legacy would be very difficult to duplicate. She had a deep interest in gardening, and prior to crossing the pond, she attended a “ladies horticultural college”, which of course, no man took seriously. She went into horticulture at a time when nice young ladies were expected to get married and have a family (which she never did), and she rolled up her sleeves and got things done! Her determination and persistence inspire me, and the plants she introduced speak of an unsurpassed skill and talent for hybridizing. Her introductions are still respected and grown all over the world; many of which have never been duplicated. Her cultivars are often still the standard by which any new cultivars are judged.

When she was nearly 40, she enrolled in the Ontario Agricultural College (now the University of Guelph) with an interest in developing fruit trees for short growing seasons. She was eventually hired to work as a “day laborer” for minimum wage at the Ottawa Experimental Farm, but she very quickly proved herself more than capable in what was then a strongly male dominated field. She was noticed by W.T. Macoun (another famous Canadian gardener) who eventually offered her a prominent position. It was meant to be temporary (“until a proper man for the job could be found”) but she never left.

She became the first female hybridizer working in Canada, and she started with lilies. Her work with lilies was exceptional, and got her significant attention and international acclaim. It led to her beginning to experiment with Siberian irises, crabapples, and then roses. It seemed whatever she touched turned to gold; she was ruthless at yanking out inferior seedlings or hybrids and went to great lengths to obtain pollen, cultivars, and species. She was determined to make a go of it and she was successful with nearly every plant she turned her hand to. The white Siberian iris ‘Snow Queen’ was hers, and its equal has never been developed. The flowering crabapple ‘Makamik’ is also hers, and I dare say it is one of the grandest cultivars ever to be introduced. While most of her roses are no longer available (she developed over 20 cultivars), she absolutely laid the ground work for Dr. Felicitas Svejda to begin what would become the ‘Explorer’ series- perhaps the most famous and hardy series of roses in Canadian history.

However, what she is best remembered for is her lilacs. Perhaps no one in history has ever devoted themselves to lilacs the way Isabella Preston did, and it would be difficult to find anyone in any country who has ever worked so hard for the advancement of horticulture. Throughout her life, she introduced 81 cultivars of lilacs, 47 of which are still available. She started with crossing various species lilacs with well known French hybrids. Her goal was to widen the color range of lilacs even further, eliminate suckering, and introduce forms with more compact growth habits and heavier blooming capacity. She succeeded in every one of these goals. Preston lilacs are now grown in cold regions all over the world and remain much loved landscape shrubs at home in Canada, which is something that she wanted.

In her work with lilacs, Isabella corresponded with gardeners and botanic gardens all over the globe. One person who was especially helpful to her was James Macfarlane, the head gardener at the Edinburgh Botanic Garden in Scotland. She visited him several times, and he visited her. She named her best pink lilac for him, and although there is no evidence of this, I hope (I HOPE!) that they loved each other passionately and that they had a torrid and lengthy affair that was based on mutual affection for lilacs. After she retired, she spent a year traveling in England and then returned home to Ontario, where she gardened quietly until her death. Always modest about her achievements, Isabella named just one of her introductions for herself; the beautiful lilac ‘Isabella’ that she chose to bear her name is still available.  In 2007, the Canadian government finally honored her by producing postage stamps featuring two of her lilac introductions.

Since there are literally hundreds of lilacs, I can’t possibly introduce you to all of them. For the sake of time and brevity, I have narrowed it down to just under 30 varieties. I have arranged these lilacs alphabetically, but these are my very favorite recommendations.

‘Agincourt Beauty’- (French) Very compact and growing only 7-8 ft. tall and wide. The flowers are intensely fragrant, and rich, deep purple.

‘Albert Holden’- (French)- Probably the smallest of the French lilacs, growing only 6 x 6. The flowers are extremely fragrant and deep purple in color, with paler buds. This creates something of a two toned effect. It’s a vigorous grower and especially nice if you don’t have space for a full size lilac.

‘Avalanche’- (French)- Very compact and very fragrant, this is a beautiful pure white lilac. We don’t have enough white in our gardens as a rule, and we certainly don’t have enough white lilacs!

‘Beauty of Moscow’- (French)- Also called ‘Krasavitsa Moskvy’. Considered to be one of the very best “two tone” lilacs, and easily one of the most highly coveted and sought after lilacs in the world. This variety produces huge clusters of shell-pink buds that open to semi-double and double white blooms. It is definitely fragrant, though not as strongly fragrant as others. Growing around 12 ft. tall, this variety has a tendency to get a bit leggy at the base and tends to flower well in alternating years.

‘Belle de Nancy’- Found in practically every old neighborhood in Canada, this very common and beautiful lilac produces very fragrant, light purple-pink blooms from dark buds. It is very fragrant, and sometimes produces semi-double blossoms.

‘Bloomerang Purple’- If ever there were a plant to stir up controversy, this is it. Introduced by Proven Winners, this (trademarked) cultivar has become an object of much heated debate. Lilacs are genetically programmed to flower in late spring or early summer, but one species is known to occasionally flower again in late summer, albeit infrequently and much less profusely. Proven Winners has somehow created a lilac that flowers normally in early summer, and then again in late summer or early fall. The second crop of blooms are much smaller in size than the first crop, and produced much less profusely. (This is not promoted.) There are a large number of gardeners who feel that both the color and scent of lilacs is completely out of place in September, and others who think this is fantastic. I am deeply bothered by having a genetically manipulated lilac out there. I also dislike the overly cutesy name they have chosen for it. The fact that they have chosen to put the word purple in the name strongly suggests to me that they intend to release a series of reblooming lilacs. I worked in garden centers for many years, and when this variety hit the market, the first thing I noticed was how exorbitantly expensive it is. ($65.00 for a fairly small plant.) There was also a lengthy list of things we could not do to this lilac. It could not be exposed to cool, wet conditions prior to leafing out or it would get bacterial disease. We were not to get water on the foliage once they did leaf out, as this could lead to fungal issues. I’m quite serious when I tell you that we got an entire page of care instructions from the grower and this was before they even hit the sales floor! Isn’t one of the reasons we grow lilacs because they are so care free? I don’t want a lilac that behaves like a tea rose! Further, the flowers are not especially fragrant and I had several customers complain of tipkill and dieback. I neither want nor need a lilac that reblooms in the fall. Victor Lemoine is probably rolling over in his grave!

‘Charles Joly’- (French)- Slower to establish than many of the other French lilacs, this variety produces beautiful reddish-purple, semi double to double flowers. The fragrance is somewhat less than other French lilacs, but the color is different enough to make up for this.

‘Congo’- (French)- Just as the Congo was once considered the “darkest” part of Africa, this is probably the darkest of all the French lilacs. Deliciously scented, huge clusters of extremely dark purple flowers appear in great profusion. Common throughout Canada.

‘Dapple Dawn’- (French)- This is a very special lilac, with blue-purple flowers that appear somewhat less profusely and are somewhat less fragrant than many other varieties. What’s the draw? Intensely variegated foliage. New growth is heavily streaked and splashed in shades of cream and gold and the foliage is quite showy. The variegation mostly fades and disappears as the summer goes on, and it is grown as more of a novelty than anything else, but it’s quite interesting, and many lilac enthusiasts simply have to have one.

‘Evangeline’- (French)- Oh, what a fabulous variety this is! The flowers are best described as magenta! They are very showy, often semi-double, and heavily scented. This is one of few lilacs to produce any fall color; some years the foliage will become purple in autumn.

‘Isabella’- (Preston)- The only lilac that Isabella Preston named for herself, she considered this her finest work. (High praise indeed.) Extremely compact, this variety only grows 4 x 4 and flowers so profusely that it’s very common that leaves cannot even be seen!!! The abundance of flowers is absolutely incredible! The blossoms are a soft lavender in color, beautifully scented, and the foliage often becomes a gorgeous burgundy or bronze in the fall. It received an award of merit from the Royal Horticultural Society in 1941.

‘James Macfarlane’- (Preston)- Very compact and only growing about 8 ft. tall, this is widely held to be the best pink lilac in the world. The flowers appear quite late, in large clusters, and the fragrance is beautiful. It is an extremely profuse bloomer and was named for the curator of the Edinburgh Botanic Garden, who was a great friend to Isabella Preston. How nice that she named such a stunning variety in his honor.

‘Katherine Havemayer’- (French)- This variety tends to be less compact and a bit more leggy than many of the other French lilacs, but none the less, it has been loved for decades. It has also received an award of merit from the RHS. Dark buds open to light purple, heavily scented, semi-double blooms. It flowers prolifically and can be found in many Canadian neighborhoods.

‘Ludwig Spaeth’- (French)- Nearly every gardener would recognize this lilac, even if they didn’t know its name. This is one of the most common, widely cultivated lilacs on earth. It has rich purple, heavily scented blooms and has received an award of merit from the RHS. This is what most people picture when they think of lilacs, and it is a staple in gardens across Canada and Europe.

‘Madame Lemoine’- (French)- Absolutely stunning, double white flowers. This is widely regarded as the most fragrant of all the white lilacs. Popular throughout the world, it too, has received the award of merit from the RHS.

‘Maiden’s Blush’- (French)- One of the more compact of the French lilacs, this is another widely cultivated, very widely recognized lilacs. It has light purple flowers that rapidly age to soft purple and the fragrance is powerful. It is also usually the very first lilac to be in flower.

‘Minuet’- (Preston)- Only growing about 7 ft. tall, this is a very profuse bloomer with light purple blooms that age to a soft pink. The blooms are quite late to appear, and this makes it valuable for extending the lilac season but regrettably, the flowers are only lightly scented. On the other hand, this can make it a valuable addition to the garden for those who would love to grow lilacs but cannot handle the scent due to allergies or otherwise. This is also one of the few lilacs to develop autumn coloring, usually becoming golden yellow in the fall.

‘Miss Canada’- (Preston)- Another compact lilac only growing about 7 ft. tall, this beloved variety has beautiful, soft pink blooms that are only lightly scented. It is a profuse bloomer and vigorous grower.

‘Miss Ellen Willmott’ – (French) Named for famed English gardener Ellen Willmott, this cultivar has blossoms of creamy white to ivory that are semi-double and heavily scented. (A friend of mine who grows this lilac describes it as being “the same color as vanilla ice cream.”) 

 ‘Miss Florent Stepman’- (French)- Absolutely one of the most incredible white lilacs available. Flower clusters are huge, very fragrant, and produced in abundance. One of the best white lilacs for cutting.

‘Miss Kim’ (Preston)- I absolutely adore this lilac. Passionately. I originally only bought one because my sister’s name is Kim, and I thought that since it was a Preston lilac, it would probably be a good garden plant. I was right! This is one of the most highly scented of all Isabella Preston’s hybrids, and it is extremely compact, only growing 4-5 ft. tall and wide. The flowers are very bright pink, very showy, and produced in great profusion. Good friends of mine in northern Saskatchewan lined their driveway with this variety, and every spring, to see them in bloom was really something! It flowers well even when young and the fall color, which is a rich and appealing plum purple, is long lasting and gorgeous. This is a stellar variety in every way, and its small compact size means that even rather small gardens should be able to make room for it.

‘Mount Baker’- (French)- Heavily scented and beautiful, this is the first of the white lilacs to begin flowering. It is one of the most widely grown white varieties.

‘Pocahontas’- (French)- Very fragrant, rich maroon-purple flowers. The flower clusters tend to be a bit smaller than many other varieties.

‘President Grevy’- (French)- Named for Jules Grevy, who was president of France from 1879 to 1887. This is probably the closest to “blue” that is available in lilacs; it is often described as being “powder blue” or “wedgwood blue” in color. The flower clusters are very large and intensely fragrant. This is also one of the taller lilacs, often getting as tall as 15 ft.

‘Primrose’- (French)- Another controversial lilac, though perhaps not as controversial as ‘Bloomerang’! Discovered as a chance mutation in Holland in 1949, it received an award of merit from the RHS in 1950. The flowers are a gorgeous, distinct butter yellow that rapidly ages to ivory or cream. It flowers profusely once established, but does not bloom well until it is at least a few years old. The flowers are highly scented. There are also quite a number of reports that it is considerably “more yellow” in Europe than it is in America! Many American gardeners have complained bitterly about it saying that it is barely yellow at all, and that it is indistinguishable from white lilacs! There are others (particularly the Dutch and the British) who vehemently assert that it is yellow, not white, and so the debate rages on! I have seen it in bloom only once, and it was next to a white variety. They were clearly distinct.

‘Royalty’- (Preston)- Beautiful, light purple flowers and a profuse bloomer. This is one of the most fragrant of all the Preston lilacs.

‘Sensation’- (French)- Introduced in 1939, this lilac is adequately named! This was the world’s first truly bicolor lilac- the blooms are dark purple with a very distinct, white edging around each individual blossom! It is absolutely gorgeous and unlike any other lilac you have ever seen. The flowers are richly scented, but a bit smaller than many of the other French lilac varieties.