Lilacs are flowering shrubs known for their fragrant blooms and classic appeal. They herald the arrival of spring, filling the air with their sweet scent.
Choosing Lilac Varieties for Landscaping
Choosing the right lilac variety involves considering its mature size, bloom time, and flower color. Common lilacs (Syringa vulgaris) are popular, known for their robust growth and abundant fragrant flowers, typically reaching 8 to 15 feet tall and wide. Varieties like ‘Beauty of Moscow’ (double white) and ‘President Grevy’ (double lilac-blue) are examples of large common lilacs.
French hybrids, a common lilac type, are known for their large, often double flowers and intense fragrance. Dwarf varieties, growing 4 to 6 feet tall and wide, suit smaller spaces. Examples include ‘Miss Kim’ Korean lilac (spicy scent, pastel blue to white blooms) and ‘Palibin’ (dense, light purple flowers).
Reblooming lilacs, like the ‘Bloomerang’ series, bloom in spring and sporadically through summer and fall. These compact varieties fit diverse garden settings. Tree-form lilacs, trained to a single trunk, can reach 20 feet, adding a vertical element. Choose a variety that aligns with your design and available space.
Integrating Lilacs into Landscape Design
Lilacs can provide privacy or act as fragrant focal points in landscape design. They are effective as hedges or screens, forming a dense barrier that offers seclusion and fragrance. Common lilac varieties are suited for this due to their size, typically 8 to 15 feet tall and 6 to 12 feet wide. Plant them 5 to 15 feet apart for a continuous screen.
Lilacs can be focal points, drawing attention to garden areas, especially when in bloom. Their striking flower clusters and fragrance make them centerpieces in garden beds or near outdoor living spaces. When choosing a location, consider the lilac’s mature size to prevent overcrowding and ensure it has room to develop.
Lilacs can soften building lines and add curb appeal in foundation plantings. Dwarf varieties are useful here as they won’t block windows, creating a layered look. Placing lilacs near patios or windows allows their fragrance to drift into living spaces. They also blend into mixed shrub borders, adding seasonal color and texture with plants offering year-round interest. Lilacs require full sun (at least six hours daily) and good air circulation for healthy growth and abundant blooms.
Planting and Maintaining Lilacs in Your Landscape
Proper site preparation is important for healthy lilacs. They thrive in locations with at least six hours of direct sunlight; insufficient light reduces blooms and increases disease risk. The soil should be well-drained and neutral to slightly alkaline (pH near 7.0). Heavy clay or poorly draining soil benefits from organic matter like compost to improve structure and drainage.
When planting, dig a hole twice as wide as the root ball and the same depth. For container-grown lilacs, the root ball top should be level with the soil surface; bare-root plants can be set a few inches deeper. After placing, backfill with soil, tamping to remove air pockets, then water thoroughly. Space plants 3 to 15 feet apart, depending on mature size, for air circulation and growth.
During the first year, regular watering is important for root establishment, typically once or twice a week when the top inch of soil is dry. Once established, lilacs are drought-tolerant and only need supplemental watering during extended dry periods. A light application of granular fertilizer with higher phosphorus in early spring can promote better blooming. However, over-fertilization, especially with high nitrogen, can reduce flowering.
Prune lilacs immediately after blooming in late spring or early summer. This is important because they bloom on old wood; next year’s buds form after current flowers fade, so pruning then prevents removing future blooms. Maintenance pruning involves deadheading spent flowers, which encourages more flower buds for the following year. Thinning older, less productive stems and removing dead or crossing branches improves air circulation and maintains shape and vigor. For overgrown plants, a rejuvenation prune can be performed over three years by removing one-third of the oldest stems to the ground each year.
Companion Plants for Lilac Landscapes
Selecting companion plants with similar growing conditions enhances a lilac landscape. Plants thriving in full sun and well-draining soil are suitable partners, providing interest before, during, or after lilac blooms. Peonies, with large, fragrant flowers, bloom alongside early and mid-season lilacs, offering complementary pink, white, and red hues. They can also help conceal the lower, less dense parts of lilac shrubs.
Irises, with their upright flowers, bloom just before or with lilacs, adding color to the spring garden. For continuous interest after lilacs, daylilies provide blooms from late spring into summer, with varied colors and grassy foliage contrasting with lilac stems. Catmint offers lavender-blue flowers that extend the bloom season and attract pollinators. Creeping phlox creates a low-growing carpet of early spring color, suppressing weeds and retaining soil moisture. Spirea varieties can also extend the blooming season, flowering after lilacs and offering repeat blooms.