The ‘Wonderblue’ Lilac (Syringa pubescens subsp. microphylla ‘Wonderblue’) is a compact and desirable variety for home gardeners. Its manageable size and appealing characteristics make it a popular choice for various garden settings, especially where traditional, larger lilacs might not fit.
Distinctive Qualities
The ‘Wonderblue’ Lilac stands out for its appealing attributes. Its compact, semi-dwarf nature means it typically reaches 3 to 5 feet in height and spread, making it suitable for smaller gardens and urban spaces. This plant also exhibits a reblooming habit, producing an initial flush of icy lavender-blue flowers in late spring, then continuing to bloom from mid-summer through the first frost.
Its highly fragrant flowers emerge from purple buds, opening into single, sky-blue or lavender-blue florets. These blooms are excellent for cutting, allowing their sweet scent to be enjoyed indoors. ‘Wonderblue’ Lilac features attractive, heart-shaped green leaves that maintain their color throughout the growing season. The plant also demonstrates resistance to deer browsing and common lilac diseases like powdery mildew, reducing the need for extensive protective measures.
Planting and Growing
Site Selection and Planting
‘Wonderblue’ Lilac thrives in full sunlight, requiring at least six hours of direct sun daily for maximum flower production. While it can tolerate some afternoon shade, consistent morning sun is beneficial for air circulation and disease prevention. It prefers well-drained, fertile soil and is adaptable to a range of pH levels. If your soil retains water, mound the planting area to ensure proper drainage.
When planting, dig a hole two to three times wider than the root ball and the same depth. Carefully remove the plant from its container, gently loosen any circling roots. Place the plant in the hole, backfill with soil, and tamp gently to remove air pockets. Water thoroughly to settle the soil. Consistent moisture is important during the first growing season until the plant establishes itself.
Care and Maintenance
Once established, ‘Wonderblue’ Lilac requires moderate, consistent moisture. Water every 10 to 14 days during dry periods, providing 1 to 2 inches of water weekly if rainfall is insufficient. Avoid overwatering, as lilacs do not tolerate soggy conditions, which can lead to root issues. Fertilize in early spring and mid-summer with a balanced, all-purpose organic fertilizer, following product instructions. Lilacs are not heavy feeders; excessive nitrogen can promote leafy growth over blooms. Apply a 3-inch layer of mulch around the base, spread 3 to 4 feet from the center and pulled back from the stems, to retain moisture and suppress weeds.
Pruning ‘Wonderblue’ Lilac should occur immediately after its initial spring flowering. This timing is crucial because lilacs form next year’s flower buds on old wood shortly after blooming. Pruning too late can remove these developing buds, reducing the subsequent year’s display. Light trimming after the first flush encourages new growth and promotes the reblooming cycle. To maintain shape or rejuvenate older plants, remove up to one-third of the oldest, thickest stems at ground level.
Landscape Design Ideas
The compact size and attractive features of ‘Wonderblue’ Lilac make it a versatile addition to various garden designs. It fits comfortably in small gardens, urban spaces, or as a specimen plant in mixed borders. Its mounded growth habit contributes to a neat appearance.
‘Wonderblue’ Lilac is well-suited for container gardening, especially on patios or entryways where its fragrant blooms can be enjoyed up close. It also works effectively as a front-of-border plant, for defining garden beds, or as a low hedge. Mass plantings create a striking visual and fragrant display. Its size makes it an appropriate choice for foundation plantings near homes.
Troubleshooting and Common Concerns
A lack of blooms or poor rebloom in ‘Wonderblue’ Lilac can stem from several factors. Insufficient sunlight is a common cause, as lilacs require at least six hours of direct sun daily for optimal flowering. Improper pruning, especially too late in the season, can also significantly reduce blooms.
Over-fertilization, particularly with nitrogen-heavy fertilizers, encourages lush foliage growth at the expense of flowers. Ensure the plant receives a balanced fertilizer. While generally robust, lilacs can occasionally be affected by pests like scale insects or diseases such as powdery mildew. Good air circulation, achieved through proper spacing and pruning, helps prevent fungal issues. ‘Wonderblue’ Lilac is cold-hardy, thriving in USDA growing zones 2 through 7.