|Official Plant Name||Syringa vulgaris|
|Foliage||Simple (sometimes pinnate) leaves|
|Flowers||Conical panicles; usually coloured lilac, pink or white|
|When To Sow||March, April, May, June, September, October|
|When To Prune||January, February, June, December|
Full Sun / Light Shade
Exposed or Sheltered
2.5 – 4M
2.5 – 4M
Chalk, Loam, Sand, Clay
Moist but well drained
Neutral / Alkaline
Lilac (Syringa vulgaris) is an excellent choice of shrub for many gardens.
In this simple guide, we will provide a brief introduction to this beautiful and fragrant shrub. We’ll talk about why it can be a great choice for the UK gardener, and how to go about choosing lilac for your garden. We’ll discuss where you should grow this plant and how to plant and grow it successfully where you live.
What is Lilac?
Lilac (Syringa vulgaris) is an attractive ornamental, deciduous shrub, or small multi-stemmed tree commonly grown for its showy blooms of pinkish, purple or white flowers that emerge for a short period in the late spring or early summer – just before roses and other summer flowers come into bloom.
The common lilac is in the Oleaceae or olive family. It is native to the Balkan peninsula, where it naturally grows on rocky hills. It is now widely cultivated in the UK and around the world, and has been naturalised in some parts of Europe and North America, though is not regarded as an aggressive or invasive species.
S. vulgaris was introduced to northern European gardens at the end of the 16th Century, from the influence of Ottoman gardens rather than through discovery in the wild. Today, there are many different names and cultivated varieties to choose from.
Why Grow Lilac?
Though it blooms for just a short period of time in late spring or early summer, we would still highly recommend growing lilac in your garden. While these shrubs are in flower, their beautiful pink, pale purple or white flowers are truly beautiful. And they will send a lovely scent out around your garden. What is more, even when the flowers are done for the year, the shrubs themselves will continue to add architectural height and structure to your outside space.
The flowers won’t just be great for you. They are also fantastic for attracting bees and other pollinators such as butterflies and moths to your garden. So they are a good choice for a wildlife-friendly garden, especially when combined with other plants that bloom at different times of year, or over a longer period.
The flowers can also be a useful yield. They are not only beautiful but due to their fragrance, can also be used in projects inside your home. You can make an essential oil, or an infused oil that can be used in perfumery, and in a range of natural DIY cleaning or beauty products.
The flowers can also be used to yield a natural green dye, green and brown dyes can also be derived from the leaves, and a yellow-orange natural dye from the twigs. The wood from the lilac is also used for pens, bowls and other small turned projects, and small carved items.
Choosing Lilac For Your Garden
There are many cultivars of S. vulgaris to consider in the UK, including:
- Andenken an Ludwig Späth
- ‘Katherine Havemeyer’
- ‘Madame Lemoine’
- ‘Mrs Edward Harding’
- ‘Alba’ (White)
- ‘Maréchal Foch’ (White)
When choosing a lilac, your primary consideration is likely to be aesthetics, and the colour and variation of the blooms. Most will have similar growth habits, though a few are more compact in form and a little less vigorous than others.
If you are looking for a smaller plant, ‘Red Pixie’ could be a good choice to consider. This is not only suitable for a small garden, it could also be grown successfully in a large pot.
One thing to note that is in this article we are referring to S. vulgaris (common lilac) but there are actually a few other species within this genus to consider… For example, S. emodi – known as ‘Himalayan lilac’. ‘Aureovariegata’ is a large deciduous shrub growing up to 5m tall, with tubular white flowers and variegated leaves. And Korean lilac, S. meyeri ‘Palibin’ with purple-pink flowers. This option is another compact lilac, great for small spaces or container growing.
Where to Grow Lilac
Lilac prefers and warm and sunny position, though it can also do well in dappled shade. It is best to make sure that the location will get at least 6 hours of sun each day. It is hardy to zone 5 in the UK.
The ideal place to grow lilac is in a deep, fertile and well-drained loam. However, this is a plant that can succeed in most soils, including chalk. The one thing to note is that it does not perform at its best in acidic soil conditions.
Lilac is very useful as part of an informal, wild, mixed hedgerow or in a traditional border, where it will be great for adding height and structure at or close to the back of the bed.
Lilac is usually purchased as a pot grown plant. In order to plant it you should simply dig a generous hole. Plant the lilac in the ground to the same level that it was in its pot. Fill back the soil around the root system and tamp it down gently around the plant.
At the time of planting, it is a good idea to mulch well in the area around your new lilac with a good quality organic mulch. For example, you could use wood chip, autumn leaves, leaf mould or a good quality home-made compost. Lilac will thrive in soils with a high organic matter content (plenty of humus).
Lilac can also, however be grown from seed, or from cuttings. Seeds are tricky for novice gardeners as they must be pre-treated with four warm weeks, then three weeks of cold stratification which will improve germination rates. The seeds that germinate successfully should then be pricked out into individual pots when they are large enough to handle, and planted out in summer, or late spring the following year.
Cuttings from young shoots can be taken in June. Take 7cm long cuttings, with a heel, and place them into a cold frame. Semi-ripe cuttings can also be taken and placed into a cold frame in July or August.
Branches can also be layered (bent over and secured touching the soil) in spring before new growth begins. They should root by the same time the following year.
However, if you or a friend, relative or neighbour has a lilac that you admire, the easiest way to propagate it for your garden is to divide one of the suckers that emerge around the parent plant in the late winter. Suckers can simply be planted right away into their new growing positions. Lilacs will tend to sucker freely if they are growing in a suitable spot.
Caring For Lilac
Lilacs can be prone to certain problems, such as lilac blight, honey fungus, leaf mining moths, and thrips… but are usually relatively trouble-free plants that will not require a lot of care.
After the flowers fade, as midsummer approaches, you can deadhead the spent blooms and may, if you wish, prune the shrubs for height and shape.
If you have a larger pruning job to do (if, for example, you have a large, mature lilac that you want to renovate) then it is best to leave this job until winter. During this period, the lilac is dormant, and you can get away with removing a lot more material from the plant.
Lilacs do respond well to hard pruning, so you can be quite brutal if you would like, for example, to considerably reduce the height of an existing specimen. But it is important to note that if you do prune hard, you will not get any flowers the following year. This is because lilacs flower on the previous year’s wood. So you will have to wait at least a year for further blooms as you will have to wait for the branches to regrow.
You can prune while still maintaining flowering by removing alternate stems, cutting them back to the ground. You can also simply stick to a basic pruning clean up and just remove any dead, diseased or damaged wood. You can also simply prune lightly to maintain shape over the winter months.
A permaculture garden designer, sustainability consultant and freelance writer, Elizabeth works as an advocate for positive change. She aims to inspire others to reconnect with nature and live in a more eco-friendly way. She also tries to practice what she preaches as she tends her own forest garden, polyculture beds and polytunnel. See her personal website here.