Lilac Bushes & Trees
Nothing says that spring is here like the sight and smell of lilacs. These bushes, adored by many, speak of the spring that always returns, as they did for the poet Walt Whitman, who described them as ‘this bush in the dooryard, with delicate-color’d blossoms and heart-shaped leaves of rich green’. For the practical-minded gardener, they are valuable, hardy and colorful shrubs, offering a profusion of blooms in a wide range of colors, on easy to grow plants.
Like so many of our garden plants, lilacs went through a big phase of breeding in the late 19th and early 20th centuries, which has continued in a smaller way up to today. As a result, we have a wonderful range of beautiful plants available to us, and no matter where you live or what kind of garden you have, there is a Lilac Bush that is perfect for you.
The name lilac comes from a Persian word ‘nilak’, which means ‘bluish’, and this bluish-purple color is so special and unique that we call it ‘lilac’, being the natural color of many plants in this group. Over the years, with intensive breeding and selection, a whole palette of other colors has been created, from pure white, through creams, pale and dark pinks, into shades of lilac, rich purple-reds, and the deepest purples too. The large flower clusters festoon the bushes in spring, shortly after the new leaves appear, and they fill the air with an evocative, sweet perfume. Cut and placed in vases they will fill your rooms with that heady fragrance, and in the garden their bright colors tell us that finally spring has truly arrived.
Appearance of Lilac Trees
Lilacs are mostly large bushes or small trees, often with one or several slender trunks, and an upright, rounded crown of branches. There are also smaller shrub varieties. The deciduous leaves are heart-shaped, mostly with a smooth, slightly glossy surface, and a smooth margin. The leaves are deep green, making an attractive background color in the garden, and they turn yellow in the fall, before dropping to the ground. The bark of the stems is usually gray and smooth, or rougher in older stems.
Each flower is small, perhaps a quarter-inch or so across, but they are carried in large clusters, called panicles, of many hundreds of flowers, shaped like a tall pyramid, slightly drooping, and up to eight inches or more in length. There are many colors of flowers, even including some soft yellows, as well as the more familiar pinks, lilacs and purples.
Lilac Bushes are typically 6 to 15 feet tall, but their size can be modified by pruning. Some are smaller, and the Tree Lilac, which is an entirely different species, grows into a medium-sized tree, reaching 20 or 30 feet.
Using Lilac Bushes in Your Garden
Lilacs can be used in many ways in your garden. The most popular is to plant them as background shrubs behind later-blooming shrubs. This way, they will be wonderful in spring, and fade into the background as effective green screening for the summer. They are also good choices for specimens planted on a lawn, or as an avenue, well-spaced apart, along a driveway. They can also be grown in a hedge, alone or mixed with other flowering shrubs, to create a very attractive flowering privacy screen along your property boundary, or to block out an ugly view.
Growing and Caring for Lilac Bushes
Lilac Bushes are easy to grow, and they will grow in a wide range of climates, soil conditions and light levels. To begin with climate, considering their beautiful flowers, these plants are remarkably cold-hardy. Many grow well in zone 3, with winter temperatures plunging to minus 40 degrees, all the way through to zone 7, so across a huge swath of the country, from east to west, these plants will thrive. Some newer hybrids even grow well in zone 8, which opens up almost the whole country, including southern California, to lilac growing.
From sandy soils to clay, and from mildly acidic to mildly alkaline, most soils will support lilacs with little difficulty. They do enjoy a moist, well-drained soil best, and lack of moisture in summer will reduce flowering the next year, but in most of the cooler areas where they grow, summers are rarely exceptionally dry, and well-established plants are moderately drought resistant.
To flower well, lilacs need sunlight, although they will also grow well in partial shade, as long as there are several hours of direct sun for parts of the day. They are usually free of major pests and diseases, especially if pruned correctly, to keep newer stems growing from the base. In dry humid summers, in shade, or when lacking water, your bushes may develop a grey, dusty look on the leaves, but this is harmless, if a little unsightly, and growth the next year will be perfectly normal.
Most Lilac Bushes benefit from regular pruning, done soon after flowering. In young plants, just shorten back the branches by about one-third, to encourage denser growth. In older bushes, removing a few of the oldest branches completely at ground level each year will keep your bushes vigorous and healthy. Remove no more than one-third of the branches, and cut back either to the ground, or to a strong side-shoot. If you let your bushes grow on just one or two old stems, there is a danger that these will be infested with the lilac borer moth, which can kill the stems. Keeping several younger stems always developing prevents this problem. For the best blooming, remove as many as you can of the old flower heads, as soon as they fade.
Most Popular Types of Lilacs
Of the 20 species of lilacs, only a few are grow in gardens, and the most important species by far is the common lilac, which has been highly bred to develop the many varieties we have today. Because of its importance, we will look at that plant first, before considering some other useful kinds of garden lilacs that deserve more attention, as they have lots of merits.
The common lilac, syringa vulgaris, came originally from the Balkan area of Europe, where modern-day Serbia and Croatia are. It has been widely grown across almost all Europe and North America for several hundred years, and in many places it now grows wild. Unlike some other alien species, it has not spread aggressively, and it is usually found where there were once homes or farms, and it does not spread into wild areas to any great extent.
The original plant is a small tree or shrub, which grows to around 20 feet tall, and forms a dense thicket of stems, since it grows new shoots from the base each year. The flower clusters are around 4 to 6 inches long, and a lilac to mauve color, or sometimes white. The wild tree has been grown in European gardens since the 16th century, and was brought to America by the early settlers who grew it extensively in their gardens. There were certainly variations in color and form among those early plants, but it was in the 19th century that most of the varieties that grow today were developed.
Victor Lemoine came from a long family line of professional nurserymen, and after studying and working at several important nurseries in Europe, he established his own nursery in 1847 in the town of Nancy. He was a passionate plant breeder, and worked with many different plants to create new colors and forms. He is most remembered for his lilacs, which he began breeding in 1870. He started with a not-very-interesting variety with double flowers.
That is, each tiny flower had extra petals, making the flower cluster fuller and denser. With the help of his deft-fingered wife, Marie Louise, and his son Émile, he crossed and re-crossed different forms and colors, finally creating over 200 varieties. They all had large, fragrant flowers and came in a wide range of colors, many with full, double flowers as well. His plants were hugely popular, and were quickly distributed around the world.
Many of the most popular varieties grown today are Lemoine’s, and they are usually called ‘French Lilacs’. There has been more breeding since then, chiefly to overcome two limitations in his plants. The first is their need for a lengthy period of cold nights in winter to bloom, limiting them to zone 7 or colder. The second is that these plants only flower once a year, and some gardeners find the plants boring when not in bloom. Breeders have worked to develop plants that bloom again in late summer, and there are today some top-class varieties that do just that, extending the value of these plants considerably.
French Lilac Varieties
|Name||Height ft.||Spread ft.||Features|
|Bridal Memories||8-10||8-10||Pure white blooms filled with perfume|
|Lavender Lady||3-6||3-6||Specially bred for zone 8|
|Bloomerang||4-5||4-5||The best repeat-blooming variety around|
Bridal Memories – This pure-white variety of French Lilac is the pinnacle of the group, and a plant worthy of a place in every garden. White lilacs are strongly associated with spring weddings, and this plant makes the perfect garden memory of that great event. Even if you simply use it as a garden shrub, you will adore the purity of its clean, white color, and the drama it brings to the garden. Easily grown, and staying small, at around 8 to 10 feet, this variety is our number one choice. It represents just one of the many varieties of French Lilacs available in many colors.
Lavender Lady – Most lilacs need a significant period of cold during winter to form their buds, but this variety is different. Walter Lammerts was a plant biologist at UCLA who joined forces with the founder of the LA Daily News, E. Manchester Boddy, at his estate in LA called Descanso Gardens. There he developed a number of ‘low-chill’ lilacs that would grow well in southern California. He created ‘Lavender Lady’, still considered the best. With its pink-lilac full blooms and rich perfume, this lilac will satisfy anyone in zone 8 or even zone 9 who craves for the classic look and smell of lilacs.
Bloomerang – The dream of lilacs blooming after spring remained a dream until, in 2006, Timothy Wood, of Spring Meadow Nursery in Michigan bred Bloomerang, a hybrid lilac more exactly called ‘Penda’. This small plant, growing to just 4 feet by 4 feet, and perfect for small gardens, has large purple blossoms. Its great virtue is that after a full blooming in spring, it continues to produce further blooms throughout summer and all the way into August. So instead of a plain green bush, we have a colorful plant that adds interest, brilliance and perfume to the summer garden too.
Other Lilac Bushes
As well as the many varieties of the common lilac, there are a number of other selections and hybrids of lilac species, some similar to, and some very different from the common lilac. Several of these are excellent small shrubs for smaller gardens, planters and even large pots, while others are big, bold shrubs for filling large spaces, and one is a full-sized tree, very different from what we think of as a ‘lilac’.
|Name||Height ft.||Spread ft.||Parentage||Features|
|Miss Kim||4-9||5-7||Syringa pubescens subsp. patula||Compact, colorful, resistant to heat and mildew|
|Paliban||4-5||5-7||Syringa meyeri||Prolific bloomer with purple-pink flowers|
|Tinkerbell||6||5||Syringa meyeri x pubescens||Wine-red fragrant flowers, hardy in zone 3|
|James McFarlane||8-10||10-12||Syringa josikaea x komarowii||Large, very-hardy, later blooming, pink flowers|
|Japanese Tree Lilac||20-30||15-25||Syringa reticulata||Excellent small flowering tree|
Miss Kim – For a smaller garden, or a smaller space in a bigger one, this lilac has to be a top choice. This shrub is a selection of a Korean species often called the Manchurian lilac, and it is notable for its ability to grow all the way through zone 8, and its resistant to the unsightly powdery mildew that French lilacs can get in dry summers. Its slightly smaller panicles of lavender-blue flowers have the classic lilac scent, and this is a top choice for any garden. Unlike other lilacs, the leaves of this shrub give us the bonus of crimson-red fall color.
Paliban – Another Asian species, ‘Paliban’ is a selected form of syringa meyeri, which was discovered in a Chinese garden by the plant collector Frank Meyer in 1909. It has smaller panicles of lavender flowers, 3 to 4 inches long, but born in profusion, completely covering the bush in a wonderful display. This bush is small enough to grow in a planter, and it is often available as a tree-form, growing on a single, 4-foot trunk. In this form it is a great choice for a large planter, where summer flowers can grow beneath it.
Tinkerbelle – This hybrid between two Asian lilac species brings fragrance into these bush lilacs, with wine-red to pink blossoms in profusion. A neat, rounded shrub to just 6 feet tall, this variety is also hardy in zone 3.
James McFarlane – This large shrub is the most widely grown plant in a hybrid group called Preston Lilacs, or Canadian lilacs. Most of these were produced by Isabella Preston, at the Dominion Arboretum in Ottawa, Canada in the 1920s. Other breeders have produced related plants, and ‘James McFarlane’ was produced at the University of New Hampshire. They are all large shrubs, which should be remembered when planting, as they are often not given enough room to thrive. They have mildew-free leaves with a rough surface, and this one has abundant rose-pink flowers in large, loose panicles. These plants flower 2 weeks after the French lilacs, so they extend the season in the garden. As well, they are hardy even in the warmer parts of zone 2, down to minus 45 degrees.
Japanese Tree Lilac – This plant is often not recognized as a lilac, so different is it from our usual idea of these plants. It is a very attractive small tree, reaching 20 or 30 feet tall, often with several major trunks, and it is a great choice as a specimen, or as a background tree. A tree from Japan, China, Korea and Russia, syringa reticulata is unique in having creamy-white flowers in fluffy panicles in early summer. These can he 12 inches long and 8 inches across, and cover the crown of the tree is a profusion of honey-scented blooms. This useful, hardy tree will grow in zones 3 to 7, and it is an ideal choice for an easy to grow flowering tree.