President Grevy Lilac

‘President Grevy’ Lilac Care Guide

Overview & Characteristics

• President Grevy is a French Lilac cultivar known for its fragrant, double lavender-blue flower panicles borne in late spring. 

• It is an upright deciduous shrub, with light green, heart-shaped leaves. 

• Typical mature size: 10–12 ft tall by ~8–10 ft wide (some sources also list up to 12–15 ft height) 

• Hardiness Zones: 3–7 (or similar) in many catalogs.

• Best flowering occurs in full sun (at least 6 hours of direct light) and well-drained soils. 

1. Planting & Site Conditions

• Sunlight: Choose a location with full sun (6+ hours). It tolerates light shade but may bloom less. 

• Soil: Prefers rich, humus-rich, well-drained soil. It is tolerant of alkaline or neutral soils; dislikes overly acidic or waterlogged soils. 

• Soil Drainage & Elevation: If planting in heavy or poorly drained soils, consider raising the planting bed or improving drainage. 

• Air Circulation: Good airflow around the plant helps reduce disease, especially mildew or fungal issues. 

• Spacing: Leave sufficient space (e.g. ~8–10 ft) for mature width and air circulation. 

2. Watering & Establishment

• During First Years: Keep soil moist, but not soggy. Water deeply to encourage root development.

• Once Established: Lilacs are fairly drought tolerant; supplemental watering during long dry spells helps maintain vigor and flowering. 

• Mulching: Apply a 2–3 in layer of organic mulch around the base to hold moisture and suppress weeds, but keep mulch away from the trunk.

3. Fertilizing

• Use a balanced slow-release fertilizer in early spring before new growth begins.

• Avoid high nitrogen fertilization, which may promote leafy growth at the expense of flowers.

• Incorporating compost or organic matter at planting and annually can support soil health.

4. Pruning & Maintenance

• Timing: Immediately after flowering (late spring) is the best time to prune. 

• How to Prune:

  • Remove spent flower clusters (deadheading) to reduce energy spent on seed production. 

  • Remove dead, diseased, or crossing branches. 

  • To maintain vigor and shape, up to one-third of older stems may be pruned back to ground in successive years (renewal pruning) to encourage fresh wood.

  • Prevent root suckers (if any) by removing them early. 

5. Flowering, Foliage & Seasonal Interest

• Bloom Time: Late spring (timing depends on climate) with showy, fragrant panicles of double blossoms. 

• Foliage: Heart-shaped light green leaves during summer. 

• Fragrance & Attractiveness: Highly fragrant, attracts pollinators like bees and butterflies. 

• Fall / Winter Interest: While its main show is spring flowers, it still provides structure, and the bare branches can frame winter scenes.

6. Pests & Diseases

• Generally robust, but potential issues include:

  • Powdery mildew or leaf mildew especially in humid, poorly ventilated conditions.

  • Lilac blight and occasional pests (leaf-miners, thrips) may occur. 

• Prevention:

  • Maintain air circulation by spacing and pruning.

  • Avoid overhead watering.

  • Remove and destroy any diseased wood promptly.

7. Winter & Cold Hardiness

• Very cold-hardy (Zones 3–7) — generally survives winters well in northern climates. 

• In exposed or windy sites, a layer of mulch helps buffer root zone.

• Young plants may benefit from some winter protection or screening in their first years.

8. Landscape Uses

Specimen shrub — great focal point for fragrance and spring bloom
Flowering hedge or screen when multiple plants are used
Mixed shrub border — pairs well with later-blooming plants so flowering interest continues
Cut flowers — the fragrant blooms are good for cutting and bringing indoors