Common Lilac (Syringa vulgaris)

How much light does a Common Lilac need?

Lilac grows and flowers best in full sun, which means six or more hours of direct light each day. It also tolerates part shade, but less sun reduces flowering and raises the risk of powdery mildew. Give this shrub the sunniest site available, since full sun supports both strong bloom and better resistance to disease.

• Light: Full sun and part shade (full sun preferred)^1,2

How often to water a Common Lilac

Lilac needs a medium amount of water, neither too little nor too much. Keep the soil moist but well-drained, and avoid letting water collect in wet ground that drains poorly. Avoid pairing wet, poorly drained soil with heavy watering, since the plant needs just a medium supply.

• Water: Medium³

Best soil for a Common Lilac

Plant common lilac in soil that drains well but still holds some moisture, rather than soil that stays wet or bone dry. This shrub does best in neutral soil, with a pH somewhere between 6.0 and 8.0. Avoid soil that stays soggy after rain and soil that dries out completely, since this plant needs soil that is evenly moist but well-drained.

• Soil drainage: Well drained and moist²
• Soil pH: pH 6–8¹

Hardiness and temperature

Common lilac is hardy in USDA zones 3a through 7a, a range that runs from 3a up through 3b, 4a, 4b, 5a, 5b, 6a, 6b, and 7a. It is native to Bulgaria, Greece, Romania, and the region once known as Yugoslavia. It is also classified as introduced, not native, in the US-L48 listing.

• Hardiness: Zones 3a–7a^1,2

Pruning a Common Lilac

Prune common lilac through deadheading, light shaping, and occasional hard renewal pruning. For hard renewal, periodically remove the oldest and biggest stems all the way down at ground level. Use light shaping and deadheading as the lighter, regular pruning tasks for this shrub.

• Pruning: Deadheading, Hard renewal pruning and Light shaping⁴

How to plant a Common Lilac

Plant common lilac somewhere within USDA zones 3a to 7a, where it can survive the local winter. Give it room to grow, since a mature plant reaches 8 to 15 ft (2.44-4.57 m) tall and 6 to 12 ft (1.83-3.66 m) wide. Space new plants far enough apart to match that mature spread, so they are not crowded once full-grown.

• Hardiness: Zones 3a–7a^1,2

Winter care

Common lilac, which is deciduous, stays hardy outdoors through USDA zones 3a to 7a, the full range recorded for it. That hardy range is also simply described as zones 3 to 7, unless a specific cultivar is otherwise noted. Common lilac is a deciduous shrub.

• Hardiness: Zones 3a–7a^1,2

How to propagate a Common Lilac

You can propagate common lilac from stem cuttings or by grafting onto rootstock. Most plants sold at nurseries are grafted rather than rooted from cuttings. Because grafted plants can send up suckers from the rootstock, you should remove those suckers when you see them. Grafting and stem cuttings are the two propagation methods recorded for this shrub.

• Propagation: Stem cuttings and grafting¹

Common problems

Common lilac can attract scale insects, borers, leaf miners, thrips, caterpillars, and oystershell scale. It is also known to be affected by powdery mildew, septoria leaf blight, verticillium wilt, ascochyta blight, bacterial blight, phytophthora shoot blight, witches broom, and pseudocercospora leaf spot.

• Common pests: scale insects, borers, leaf miners, thrips, caterpillars and oystershell scale¹
• Common diseases: powdery mildew, septoria leaf blight, verticillium wilt, ascochyta blight, bacterial blight, phytophthora shoot blight, witches broom and pseudocercospora leaf spot⁵

Questions and answers

What growing conditions does common lilac need?

Give it full sun for the best bloom, though it tolerates part shade. Plant it in neutral soil, with a pH between 6.0 and 8.0, that drains well but stays moist. It needs a medium amount of water rather than heavy or dry conditions.

Which pests and diseases affect common lilac?

Common lilac can attract scale insects, borers, leaf miners, thrips, caterpillars, and oystershell scale. It is also affected by powdery mildew, septoria leaf blight, verticillium wilt, ascochyta blight, bacterial blight, phytophthora shoot blight, witches broom, and pseudocercospora leaf spot.

How do you propagate common lilac?

You can propagate it from stem cuttings or by grafting onto rootstock. Most nursery plants are grafted, so remove any suckers that grow from the rootstock.