General
Common lilac (Syringa vulgaris) is a long-lived, cold-hardy flowering shrub valued for its intensely fragrant spring blooms. It forms an upright, multi-stemmed framework and can be grown as a specimen, informal hedge, or part of a mixed border. Flower buds for next spring are typically formed on this season’s growth shortly after flowering, which is why pruning time matters. Lilacs can live for decades when planted in the right spot: sunny, airy, and well-drained. Many garden lilacs are grafted or grown on their own roots; some types may produce suckers, which can be used for propagation or removed for a cleaner shape. If you want maximum fragrance and bloom, prioritize sun, avoid excess nitrogen, and keep the shrub rejuvenated by removing old stems over time.
Light
Full sun to partial shade. For best flowering, aim for at least 6 hours of direct sun and a site with good air movement.
Soil type
Well-drained loam or clay-loam is ideal, preferably neutral to slightly alkaline. Lilac tolerates clay if it drains, but struggles in compacted, waterlogged soils.
Water requirement
Medium; drought tolerant once established. Water deeply during the first 1–2 seasons and during prolonged dry spells, especially while forming next year’s flower buds in summer.
Nutrient requirement
Medium; thrives with moderate fertility. Too much nitrogen produces lush leaves but fewer flowers—use compost and gentle, balanced feeding rather than strong lawn fertilizers.
Planting
Plant in early spring or early autumn when temperatures are cool and soil moisture is more reliable. Choose an open, sunny location with good airflow; crowding against walls or dense shrubs can reduce flowering and increase mildew. Dig a hole wider than the root system and loosen the surrounding soil so new roots can expand. Plant at the same depth as in the pot; for bare-root plants, spread roots naturally and backfill with native soil improved with a little compost if needed (avoid turning the planting hole into a rich ‘pot’ in very different native soil). Water in thoroughly to settle soil around the roots. During the first growing season, water deeply when the top few centimeters dry out—aim for fewer, thorough waterings rather than frequent shallow sprinkling. Mulch lightly with compost or leaf mold, but keep mulch a few centimeters away from the stems to prevent rot. Space plants with their mature size in mind; good spacing improves airflow and keeps flowering strong.
Pruning
Prune immediately after flowering because lilacs bloom on old wood. Start by removing spent flower clusters (optional but tidy), then focus on structure. Each year, remove dead, damaged, or crossing stems. For rejuvenation, remove some of the oldest, thickest stems at ground level—ideally 1/4 to 1/3 of the oldest stems per year over 2–3 years—so the shrub constantly replaces old wood with vigorous new shoots. Avoid shearing the whole shrub like a hedge if you want flowers; shearing removes the wood that would bloom next spring and creates dense outer growth with shaded, weak interior branches. If you must reduce size, do it gradually right after bloom, cutting back to a strong side shoot rather than “topping.” Suckers can be removed at the base to keep the shrub contained, or a few can be selected to replace older stems.
Maintenance
Top-dress with compost at planting and again lightly during the growing season if growth slows. Because wild rocket is perennial, aim for steady but modest fertility: too much feeding can reduce leaf quality and increase pest issues. Water during prolonged drought—consistent moisture helps keep leaves tender and supports faster regrowth after cutting. In very wet soils, improve drainage (raised bed, lighter mix) to avoid winter and spring crown rot. In containers, use a well-draining mix and don’t let pots dry completely. Consider fine insect netting over young plants if flea beetles are a recurring problem; established plants often tolerate some damage better than seedlings.
Harvest
For indoor arrangements, cut flower clusters when most buds are colored and just beginning to open. Harvest early in the day, place stems immediately in water, and recut stems at an angle. Removing some flowers can be combined with deadheading, but avoid stripping the shrub heavily if you want the fullest display outdoors.
Common issues
Powdery mildew can appear in humid weather or shade; it usually looks worse than it is. Improve airflow, avoid excess nitrogen, and keep the shrub in sun. Poor flowering is most often caused by too little sun, pruning at the wrong time (late season), or overly rich/high-nitrogen feeding. Dieback can occur in waterlogged or compacted soil—improve drainage and avoid mulch piled against stems. Suckering is common in some plants; remove unwanted shoots early or use them to propagate if the plant is on its own roots.
Pollination
Insect-pollinated; highly attractive to bees and other pollinators during bloom.
Companion plants
Peonies, roses, ornamental grasses, spring bulbs, catmint, salvias, and other sun-loving perennials that enjoy similar well-drained soil.
Incompatible plants
None known. Avoid dense, thirsty groundcovers right up against the base while the shrub is establishing.
