How to Grow Lilac 'Declaration'

Lilac 'Declaration'

Syringa vulgaris 'Declaration'

shrub

Declaration is a stunning lilac cultivar known for its deep purple-red flowers with a slight fragrance. This deciduous shrub produces large, dense panicles of semi-double blooms in mid to late spring. It's a hardy, disease-resistant variety prized for ornamental landscaping and cut flowers.

Growing Conditions

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Sun: Full sun, 6-8 hours daily minimum

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Water: Moderate watering; keep soil evenly moist during growing season but allow to dry slightly between waterings. Once established, quite drought-tolerant. Reduce watering in fall to encourage hardening off.

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Spacing: 72 inches

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Days to maturity: 3-4 years to full flowering from transplant

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Planting depth: Plant at same depth as root ball; crown should be at or slightly above soil level

Soil

Type: Well-draining loamy soil, neutral to slightly alkaline

pH: 6.0-7.5

Amendments:

Compost Peat moss Lime (if soil is acidic) Aged manure

Growing Zones

Find your zone →

Thrives in zones 3-7; prefers cooler climates

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b

Growth Stages

Establishment

First year

Young plant is developing root system with minimal top growth. Single or multi-stemmed structure begins forming.

Water regularly to keep soil consistently moist. Stake if needed. Avoid pruning in first year except to remove dead wood. Mulch with 2-3 inches of organic material.

Vegetative Growth

Years 2-3

Plant grows taller and bushier, producing lance-shaped green leaves along woody stems. Frame of shrub develops.

Continue moderate watering. Apply balanced fertilizer in early spring. Prune after flowering to shape if needed—remove crossing branches and spent flower heads. Remove any weak or crossing canes.

Budding & Pre-Flowering

Late August through April

Terminal buds form along branch tips in late summer/fall. Buds swell throughout winter and early spring.

Do not prune during this period. Ensure adequate light. Buds are hardened for frost. Avoid high-nitrogen fertilizer which delays flowering.

Flowering

3-4 weeks in May (varies by zone)

Large, dense panicles of deep purple-red semi-double flowers open abundantly in mid to late spring. Heavy fragrance.

Enjoy the blooms. Deadhead spent flower panicles promptly to tidy appearance and encourage energy redirection. Water if spring is dry. Do not fertilize during bloom.

Post-Flowering & Summer

June through September

Flowers fade and are removed. Plant focuses on foliage development and new stem growth. Gradually transitions to dormancy in fall.

Prune within 2-3 weeks of bloom end if shaping is needed. Water during droughts. Apply low-nitrogen fertilizer in early summer. Remove any diseased or crossing wood. Reduce watering in fall.

Companion Planting

Plan your garden →

Plant with:

Catmint Russian sage Daylily Peony Weigela Viburnumalternifolia Lamb's ear Salvia Allium

Avoid planting near:

Black walnut Dense evergreen hedges (reduces light) Plants requiring acidic soil Areas with poor air circulation

Common Pests

Prune out infested branches. Keep trees healthy and vigorous. Use pheromone traps to monitor. In severe cases, apply insecticide to trunk in early June.
Spray with horticultural oil in dormant season (late winter). Remove heavily infested branches. Encourage natural predators.
Ensure good air circulation and full sun. Avoid overhead watering. Spray with sulfur or baking soda solution if needed. Remove affected leaves.
Remove and dispose of affected leaves. Encourage natural predators. Generally not serious enough to warrant spraying.

Uses

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Ornamental and Fragrant Bouquets

Culinary

Lilac flowers are prized for their heavy, sweet fragrance in fresh cut arrangements. While not typically eaten, they can crystallize or infuse into syrups for specialty culinary and beverage applications. [source]

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Traditional Herbal Remedy

Medicinal

Lilac flowers and leaves have been used in traditional medicine for their potential anti-inflammatory and antimicrobial properties. Lilac water and herbal infusions were historically used to treat wounds and support immune function. [source]

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Natural Fragrance and Perfumery

Household

Lilac essential oils and dried flowers are used in perfumes, colognes, and household fragrances. The distinctive floral scent makes it a popular choice for potpourri, sachets, and natural air fresheners. [source]

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Dried Flowers and Crafts

Craft

Lilac flowers dry well and can be preserved for dried arrangements, wreaths, and floral crafts. They retain their color and fragrance reasonably well when dried in low humidity. [source]

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Pollinator and Bird Support

Wildlife

Lilac blooms attract bees, butterflies, and hummingbirds during spring when few other flowers are available. The dense shrub provides shelter for nesting birds. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Cut flowers in early morning when buds are just opening. Select stems with full panicles. Cut at a 45-degree angle above a leaf node. Remove lower leaves from stems. Place immediately in water with floral preservative. Flowers last 1-2 weeks in a vase.

Fun Facts

🌱 The 'Declaration' cultivar was developed to produce flowers even more reliably and with deeper coloration than common lilacs, making it a favorite among gardeners seeking consistent performance.
🌱 Lilacs produce flowers only on old wood, which is why pruning immediately after bloom (within 2-3 weeks) is crucial—pruning later removes next year's flower buds.
🌱 A single mature lilac shrub can live 80+ years and survive in old homesteads long after other plants are gone, making them living testaments to past gardens.

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