The common purple lilac (Syringa vulgaris) is a popular spring-blooming shrub known for its fragrant purple flowers. Lilacs are native to Europe and Asia but have been cultivated in gardens around the world for hundreds of years. In this article, we’ll take a closer look at the biology, growing habits, and uses of the common purple lilac.
Botanical Description
Lilacs belong to the olive family (Oleaceae) and the genus Syringa. There are over 20 species of lilacs, but S. vulgaris is the most widely grown. It is a deciduous shrub growing 15-20 feet tall with a spread of 8-15 feet. The leaves are heart-shaped, 3-6 inches long, and arranged oppositely along the stems. The bark is grayish-brown with lenticels that give it a scaly appearance.
Lilacs produce panicles of fragrant flowers in spring. A panicle is a branched, loose cluster of flowers with the youngest flowers near the top. Each flower has a tubular base with four petals spreading outward. Flower color ranges from light purple to deep violet. There is also a white form called S. vulgaris ‘Alba.’ The flowers give way to dry, two-celled seed capsules.
Growing Conditions
Lilacs thrive in full sun and well-drained, moderately fertile soil. They prefer a soil pH between 6.5-7.5. Established plants are quite drought tolerant. Lilacs growing in shade or overly rich soils tend to produce fewer flowers. For best flowering, lilacs need a minimum of 6 hours of direct sun per day.
Lilacs grow well in USDA hardiness zones 3-7. They can tolerate cold winters and hot summers, but prefer areas with cool spring weather for optimal flowering. Flower buds can be damaged if spring temperatures rise above 85°F before the flowers open. Lilacs bloom on old wood, so pruning should be done immediately after flowering.
Common pests of lilac include scale, borer, and powdery mildew. Good air circulation helps prevent mildew. Over-pruning and high nitrogen fertilizers should be avoided to prevent susceptibility to pests and diseases.
Cultivation
Lilacs are easily propagated from suckers, cuttings, layers, and grafting. They can also be grown from seed, but plants may take up to 8 years to bloom. Named cultivars must be propagated vegetatively to preserve their characteristics.
Lilacs benefit from regular pruning to maintain shape, vigor, and flowering. Thinning cuts that remove old, unproductive wood encourage new growth and blooms. A renewal pruning method where 1/3 of the oldest stems are removed to the ground every year is ideal.
Here are some timeline tips for growing lilacs:
| Time of Year | Task |
|---|---|
| Spring | Prune immediately after flowering while cutting off any spent blooms |
| Summer | Water during drought, watch for pests |
| Fall | Mulch, remove any root suckers |
| Winter | No need to prune, lilacs are cold hardy |
Varieties
There are over 1,200 named cultivars of S. vulgaris. Here are some of the most popular varieties:
- Charles Joly – Double purple flowers on a compact shrub.
- Katherine Havemeyer – Large, fragrant double pink flowers.
- Miss Kim – Dwarf variety growing 6 feet tall with ice-blue flowers.
- Sensation – Purplish-red buds opening to white flowers with a purple picotee edge.
- Monge – Very fragrant single purple flowers blooming later than other varieties.
There are also several dwarf varieties well-suited to smaller gardens, including ‘Tinkerbelle’, ‘Bloomerang’, and ‘Miss Canada’.
History and Symbolism
Lilacs have a rich history and cultural significance. They originated on the Balkan Peninsula and were first cultivated in the 16th century. Early settlers brought lilacs to America, where they became popular garden shrubs by the late 1700s.
In the Victorian era, lilacs symbolized the first emotions of love. They were often gifted to convey affection. Lilacs also represented confidence and pride.
Today, lilacs are the state flower of New Hampshire. They signal the start of spring with their beloved blooms and fragrance.
In many places, lilac festivals are held each spring when the flowers are in peak bloom. Mackinac Island, Michigan holds an annual 10-day lilac festival that attracts thousands of visitors.
Uses
Lilacs have several uses beyond being an ornamental plant. Their sweet, floral scent has long been valued in perfumes. Lilac essential oil and hydrosols are also used in aromatherapy and natural skin care products.
Dried lilac flowers can be used to make herbal teas and potpourris. Lilacs are sometimes used to flavor jellies, syrups, and liqueurs.
The wood of lilac shrubs is dense, fine-grained, and resistant to rot. It is occasionally used for carving and making small items like tool handles and jewelry boxes.
How to Plant Lilacs
Here are some tips for planting lilacs in your garden:
- Select a planting area in full sun (at least 6 hours of direct sun per day) with good drainage.
- Amend the soil with compost or aged manure to improve fertility and drainage.
- Dig a hole twice as wide as the pot or root ball and slightly shallower.
- Set the lilac in the planting hole at the same depth it was growing in the container.
- Backfill the hole, firming the soil around the root ball.
- Water deeply after planting.
- Mulch around the base with 2-3 inches of bark, compost, or wood chips to conserve moisture.
- Prune any dead or broken branches at planting time.
For best results, plant bare root or container lilacs in spring once the ground has thawed. Space multiple plants 6-10 feet apart depending on their expected mature size.
Caring for Established Lilacs
Here is a summary of recommended care for established lilac shrubs:
- Watering – Water weekly during the first year, then only during drought. Provide about 1-2 inches per week.
- Fertilizing – Apply a balanced fertilizer or compost in early spring. Excess nitrogen can lead to floppy growth.
- Pruning – Prune soon after flowering while cutting off spent blooms. Remove around 20% of oldest stems each year to rejuvenate.
- Deadheading – Remove faded flowers to encourage additional blooming and improve appearance.
- Mulching – Maintain a 2-3 inch layer of mulch around the base. Replenish as needed.
- Pests/Diseases – Monitor for powdery mildew, borers, and scale. Improve air circulation and avoid over-pruning.
With proper siting, pruning, and occasional fertilization, lilacs can live for decades, providing beauty and fragrance year after year.
Conclusion
With their sweet scent and lovely blooms, it’s easy to see why lilacs have been a cherished garden plant for centuries. The common purple lilac offers easy care, cold hardiness, and timeless beauty. By providing full sun, well-drained soil, moderate water and pruning, these classic shrubs will thrive and delight for many years to come.
From perfumes to festivals, lilacs hold a special place in gardens and culture. Their long history and springtime display continue to capture the affection of gardeners worldwide. When planning your garden landscape, be sure to consider adding a lilac or two for their iconic flowers and fragrance.
