How to Grow Common Lilac - Plant Care & Tips

By NorwichGardener Team / 2025

Common lilac is a deciduous shrub that typically grows to 10-15 tall with an upright, spreading habit. It is most often multi-stemmed, but can be grown as a single trunk tree. It features ovate to lanceolate, dark green leaves (to 6 long) and erect panicles of highly fragrant, lilac-purple flowers (each to 1 long) in late spring to early summer.

How to Grow Common Lilac - Plant Care & Tips

Also known as

French lilac
Common lilac
Purple lilac
Syringa vulgaris
Mockorange

Things to Know

The common lilac is a fast-growing, deciduous shrub that can reach up to 10 feet in height.
It has dark green leaves and produces clusters of fragrant, purple flowers in the spring.
The common lilac is native to Europe and Asia, but has been introduced to North America, where it is now a common garden plant.
Lilacs prefer full sun and well-drained soil, and will tolerate a wide range of soil types.
They are relatively drought-tolerant once established, but will flower best with regular watering.
Common lilacs can be pruned annually to control their size and shape.
They are generally considered to be low-maintenance plants and are relatively pest- and disease-resistant.
Common lilacs are attractive to bees, butterflies, and other pollinators.
The flowers can be used in fresh or dried arrangements, and the leaves can be used in potpourris.
The common lilac is the state flower of New Hampshire and the provincial flower of Quebec.

Related plant:
Common Shrubs

How to Grow

For common lilac, first step is to find a location that receives full sunlight for at least 6 hours per day.
The second step is to dig a hole that is twice the width and depth of the root ball.
The third step is to mix the native soil with equal parts of peat moss or compost.
The fourth step is to fill the hole with the mixture and tamp it down gently.
The fifth step is to make a small mound in the center of the hole.
The sixth step is to place the root ball on the mound and spread the roots out evenly.
The seventh step is to fill in the hole with the soil mixture, tamping it down gently as you go.
The eighth step is to water the plant deeply and thoroughly.
The ninth step is to mulch around the plant with 2-3 inches of wood chips or bark mulch.
The tenth and final step is to fertilize the plant once per year with a balanced fertilizer.

Related plant:
Common Buckthorn

Soil Condition

About soil condition, common lilac prefers well-drained, organically rich soils, but it is quite tolerant of poorer soils, to the point of thriving on sandy or rocky sites. However, it does not appreciate heavy clay soils that are poorly drained. Amend heavy clay soils with lots of organic matter prior to planting.

About light

Similar to other plants, common lilacs need sunlight to grow. They do best in full sun, which means they need at least six hours of direct sunlight each day. However, they can also grow in partial shade. Too much shade will make them leggy and they won't bloom as much.

Ideal Temperature

The temperature conditions that are ideal for common lilacs are those that are cool and not too hot. They prefer a range between 60 and 75 degrees Fahrenheit. When the temperature gets too high, the plant can become stressed and may not produce as many flowers.

Humidity Level

Ideal humidity condition for this plant is 40-60%. The plant grows best in well-drained soil that is rich in organic matter. The soil should be kept moist but not wet. Common lilac does not tolerate long periods of drought.

Fertilizer Requirement

The fertilizer, this type of plant needs, is one that is high in phosphorus and potassium. This means that a fertilizer with a ratio such as 10-52-10 or something similar would work best. Be sure to apply the fertilizer to the roots and not just the soil around the plant.

Light requirement

Pruning common lilacs is best done in late winter or early spring, before new growth appears. Lilacs can be pruned quite heavily if necessary, as they are very forgiving and will quickly regrow. When pruning, always cut back to a set of buds pointing in the direction you want the new growth to go.

Plant Propagation

Propagation is the process of creating new plants from existing ones. Common lilacs can be propagated by seed, stem cuttings, or layering. Seed: Sow common lilac seeds in early spring, just before the last frost. Fill a seed tray with moistened seed starting mix and place the seeds on the surface. Cover with a thin layer of mix and press gently to be sure the seeds are in contact with the moist media. Place the tray in a warm location out of direct sunlight and keep the mix moist. Once the seedlings emerge, thin them to one per cell. Transplant the seedlings to individual pots filled with potting mix once they have two sets of true leaves. Stem Cuttings: Cut 4- to 6-inch stem sections from new growth in late spring or early summer, using a sharp knife. Remove the lower leaves from the cutting, leaving two or three at the top. Dip the cut end of the stem into rooting hormone powder and insert it into a pot of moistened perlite or sand. Place the pot in a sheltered location out of direct sunlight. Water the cutting regularly to keep the perlite moist but not soggy. Roots should form within four to eight weeks. Transplant the rooted cutting to a pot filled with potting mix. Layering: Layering is a type of propagation that can be done with many different types of plants. It is often used to propagate woody plants that are difficult to root from stem cuttings. To layer a common lilac, choose a healthy stem and bend it to the ground. Use a sharp knife to make a shallow cut in the stem. Then, cover the cut area with moistened potting mix. To hold the potting mix in place, use a small rock or a piece of wire. Keep the area moist and wait for roots to form. Once roots have formed, cut the stem and transplant the rooted plant to a pot filled with potting mix.

Growth Speed

Usually, the plant growth rate is considered fast when compared to other shrubs. New plants can grow up to 24 inches in one season. Once they are established, common lilacs can grow up to 36 inches in one season.

The Problems

Common problems for this kind of plant plants include: aphids, scale, whiteflies, borers, powdery mildew, and Verticillium wilt. All of these problems can be controlled with proper care and treatment.