Lilacs are perhaps seen as old-fashioned these days, but they are some of the most elegant and colourful shrubs flowering in May and June. They are incredibly hardy, require minimal maintenance and give off a lovely fragrance, so it seems a shame that they are not as popular as in their heyday 20 years ago, when there were around three times as many varieties available.
There are about 20 species, all hardy, deciduous flowering shrubs and small trees, found in south-east Europe and across to China and Japan. They produce fragrant flower heads in shades of lilac and mauve, of course, but also white, pink, cream and rich red/purple.
The common lilac, Syringa vulgaris, has ovate to heart-shaped leaves and trusses of large fragrant flowers. A huge number of cultivars have been bred from this species - at one point more than 500 were available before they lost popularity. But there are still excellent forms including the exotic-sounding double white flowered 'Krasavitsa Moskvy' Award of Garden Merit (AGM) and deep-purple 'Ogni Moskvy', the creamy yellow 'Primrose' AGM and the double white 'Madame Lemoine' AGM.
Other species are not as well known. A neat one, often grown as a standard for patios, is S. meyeri 'Palibin' AGM, a slow-growing variety with small rounded leaves and short upright panicles of lilac-pink flowers.
The S. x hyacinthiflora hybrids are known as early-flowering lilacs - a few weeks earlier than S. vulgaris. They are also smaller and are less likely to contract powdery mildew. The gorgeous S. x hyacinthiflora 'Maiden's Blush' AGM is a popular variety because of its masses of perfumed pink blooms, covering a compact rounded shrub.
S. x josiflexa, a race of hybrids raised in Canada, has fine deep-green leaves and loose plumes of fragrant rose-pink flowers. The best variety is 'Bellicent' AGM, with huge panicles of rose-pink flowers.
Plant Syringa in full sun or light shade. They cope with most soils, appreciating deep, fertile, well-drained conditions and actually thrive in chalky ones. It is best to buy a lilac that has its own roots because grafted plants often produce suckers.
Remove the flower heads from newly planted lilacs - this diverts the energy into root establishment. Deadhead them for the first few years even. Once established, cut out any weak shoots in winter and prune to the desired shape after flowering.
What the specialists say
Chris Lane, owner, Witchhazel Nursery, Kent
"Lilacs flower brilliantly and of course produce that wonderful scent. My main experience is with S. vulgaris. I recommend 'Ogni Moskvy', 'Kardynal', 'Maiden's Blush', 'Krasavitsa Moskvy', 'President Eisenhower', 'Blue Delft', 'Primrose', 'Souvenir d'Alice Harding', 'Madame Lemoine' and 'Sweetheart'.
"They need to be pruned like a blackcurrant, taking out older wood in rotation. Lilacs grafted onto S. vulgaris cause problems with suckering. To get round this, buy plants grafted onto privet or raised via cuttings or micropropagation."
Gordon Link, owner, The Gobbett Nursery, Shropshire
"Syringa are somewhat underrated in recent times but they are very easy to grow, completely hardy and some of the most fragrant flowering shrubs available. Among all the varieties of the common lilac that we grow, 'Krasavitsa Moskvy' takes some beating. It's a very fragrant double white that is pale pink in bud - really beautiful. If you are looking for a good blue lilac, 'President Lincoln' takes some beating, even if it has been about for years. Another favourite of mine is 'Maiden's Blush' - a gorgeous pale pink.
"The darkest lilac we grow is S. vulgaris 'Sarah Sands', but as with most of the very dark lilacs it doesn't seem to be quite as fragrant as the paler colours. If you only have room for one of the dwarf lilacs, 'Palibin' and 'Josee' are both good pinflowered varieties. But the one I wouldn't be without is S. x persica 'Alba', a slow-growing, pure-white dwarf lilac.
"There are no real difficulties when growing lilacs. They only need two things to thrive - plenty of sun and a well-drained soil - and if you can get one on its own roots you will not get any problems with rootstock suckers in the future."
Sonya Huggins, assistant gardener, Lincoln's Inn, London
"Lilacs are fantastic overlooked shrubs for a mixed or woodland-style border that gets some sun. They can also be used to make up part of a hedge because they do have a short flowering period and some consider them to look a little boring for the rest of the season.
"But I personally love the heart-shaped leaves of the common lilac and there are so many good varieties to choose from. One way to liven them up is to grow a climber like Clematis viticella through them.
"There are several varieties that do well in a patio pot. I have grown a lollipop standard form of S. meyeri 'Palibin' in a terracotta pot - its small panicles of lavender-pink flowers are charming. But it also does well as small shrub in a border, in a more natural form."
Species and varieties
- S. vulgaris 'Andenken an Ludwig Spath' AGM (H6) is a spreading, medium-sized deciduous shrub with dark-green, heart-shaped leaves and fragrant, single, deep wine-red flowers in slender panicles.
- S. vulgaris 'Primrose' AGM (H6) is a bushy, deciduous tree with heart-shaped leaves and conical panicles of fragrant, pale creamy yellow flowers in late spring and early summer.
- S. vulgaris 'Vestale' AGM (H6) is a small, bushy, deciduous tree with heart-shaped, mid-green leaves and broad, compact trusses of fragrant, single white flowers.
- S. vulgaris 'Firmament' AGM (H6) is a small deciduous tree with heart-shaped, mid-green leaves and compact trusses of fragrant, pale lilac-blue flowers, opening from pink buds.
- S. vulgaris 'Katherine Havemeyer' AGM (H6) is an upright, medium-sized deciduous shrub becoming spreading with age, with mid-green, heart-shaped leaves and compact panicles of fragrant double lavender-purple flowers that fade to lilac-pink in May and June. Height and spread: 7m.
- S. vulgaris 'Madame Lemoine' AGM (H6) is a bushy, medium-sized deciduous shrub with light-green, heart-shaped leaves and compact trusses of fragrant double white flowers from yellowish buds. Height and spread: 7m.
- S. vulgaris 'Charles Joly' AGM has heart-shaped dark-green leaves and produces dense clusters of fragrant double dark-purple/red flowers in May-June. Height and spread: 7m.
- S. vulgaris 'Sensation' AGM has single rich-purple/red flowers with distinct white edges to each petal. They are highly fragrant and appear in great trusses in late spring.
- S. x josiflexa 'Bellicent' AGM (H6) is a large deciduous shrub with arching branches and large, ovate, dark-green leaves. Clear rosy-pink fragrant single flowers are produced in long panicles. Height: 3m. Spread: 2.5m.
- S. pubescens subsp. microphylla 'Superba' AGM (H6), or the very little leaf lilac, is a bushy, spreading, medium-sized deciduous shrub with small, dark-green, broadly ovate leaves and fragrant, single, long-tubed, rosy-pink flowers in loose panicles. Height and spread: 3.5m.
- S. meyeri 'Palibin' is a bushy, slow-growing deciduous shrub with small, broadly-ovate, dark-green leaves and upright panicles of small, fragrant, lilac-pink flowers. Height and spread 1.5m.
- S. x hyacinthiflora 'Maiden's Blush' AGM is a compact rounded shrub covered in perfumed pink blooms. Height: 1.8m.
Thank you to Floramedia, which supplied the images for this article from its photo library