The Weigela shrub (Weigela florida) is known for its vibrant, trumpet-shaped flowers. Whether it blooms all summer depends heavily on the plant’s variety and the gardener’s intervention. Traditional Weigela varieties provide one spectacular flowering period, but many modern cultivars are genetically selected for repeat performances. Achieving continuous color from late spring through the summer requires understanding the plant’s biology and targeted care.
The Weigela’s Natural Bloom Cycle
A standard Weigela shrub produces its most abundant floral display in the late spring or early summer. This initial flush of blooms develops exclusively on “old wood,” which refers to the stems and branches that grew during the previous year’s growing season.
The flower buds are set in the late summer and fall, remaining dormant on these year-old branches throughout the winter. When the weather warms, these buds burst into color, typically around May or June, marking the peak of the plant’s natural cycle. Once this flowering period ends, the plant shifts its energy to vegetative growth, creating the new wood that will bear the following year’s initial blooms.
This reliance on old wood explains why the plant does not naturally bloom continuously throughout the entire summer season. Without specific intervention, the shrub will only produce one major bloom cycle annually. Newer, reblooming cultivars, however, possess the genetic trait to produce flowers on both old wood and the current season’s new growth. This difference allows them to flower a second, lighter time during the mid-to-late summer months.
Pruning Techniques for Reblooming
To encourage the Weigela to produce a second set of blooms, timely and precise pruning is necessary. The most important step is deadheading, which involves removing the spent flowers immediately after the primary spring bloom has faded. This action prevents the plant from diverting energy into seed production, prompting it instead to focus on new vegetative growth.
Deadheading should be done by clipping the faded flower stalks back to a point where they meet a healthy leaf or a side branch. This process stimulates the development of new stems, which are the “new wood” capable of forming summer flowers.
Renewal Pruning
For older or overly large shrubs, a more substantial structural pruning can be performed at this time, removing up to one-third of the overall growth. Focus on removing the oldest and thickest stems down to the ground. This practice, often called renewal pruning, promotes vigorous new shoot development from the base of the plant. Since the shrub blooms on both old and new wood for its second cycle, this fresh growth is essential for supporting the intermittent summer flowering. Complete all pruning by mid-summer to ensure the new growth has time to mature before winter.
Essential Care for Sustained Flowering
Achieving sustained flowering requires providing optimal environmental and nutritional conditions. The plant must receive at least six hours of direct sunlight daily, as full sun exposure is required for robust blooming. Insufficient light leads to sparse flowers and leggy growth, compromising the ability to produce repeat blooms.
Consistent moisture is necessary, particularly as the shrub sets its second round of buds. While established Weigela plants are reasonably tolerant of dry spells, supplemental watering during hot or arid periods ensures the new wood remains healthy and productive. The soil should remain consistently moist but must also be well-draining to prevent root issues.
Fertilization supports the plant’s two bloom cycles. An application of a balanced, slow-release fertilizer in early spring provides the necessary nutrients for the initial flush. To support the second bloom, use a formula lower in nitrogen and higher in phosphorus, as excessive nitrogen promotes leafy growth at the expense of flower development. Applying this fertilizer after the first bloom cycle helps fuel the production of new flowering wood for the summer.