Verbena is a favored garden plant, known for its extended flowering and vibrant blooms. Proper pruning is important for its health and encourages abundant flowers, keeping the plant vigorous and aesthetically pleasing.
Why Prune Verbena
Pruning verbena offers several benefits, primarily encouraging a continuous display of flowers. Removing spent blooms redirects the plant’s energy from seed production into creating new flowers, leading to more prolific and extended blooming cycles. Regular trimming maintains a desirable shape, preventing legginess and promoting bushier, more compact growth. Pruning also contributes to the plant’s overall health by improving air circulation and removing any dead or diseased foliage.
When to Prune Verbena
The timing of verbena pruning depends on the type of verbena and desired outcome. Deadheading, which involves removing faded flowers, should be done regularly throughout the blooming season, from early summer until the first frost. This encourages continuous flowering by preventing the plant from setting seed. For perennial verbena, a substantial cutback is beneficial in early spring when new green shoots emerge, usually after the last frost. This spring pruning involves cutting old, woody stems down to about 2 inches above the ground, promoting vigorous new growth and a fuller plant.
During mid-season, if verbena plants become leggy or their flowering slows, a rejuvenating cutback can be performed. This involves trimming the entire plant by up to one-fourth of its height. Trailing and groundcover types also benefit from being cut back by up to one-fourth of their stem length multiple times during the growing season to stimulate new growth and flowers. For perennial verbena in cooler climates, it is generally best to avoid heavy pruning in autumn, as leaving some dead material offers winter protection. Significant fall trimming can delay dormancy and reduce cold hardiness; cease pruning about 45 days before the average first-frost date in your area.
How to Prune Verbena
Effective verbena pruning begins with using clean, sharp tools, such as bypass hand pruners or gardening shears, to prevent disease spread. For deadheading, locate spent or faded flower clusters, which often appear dull or limp. Snip these off at the stem just behind the spent flower head. Alternatively, pinch or twist off faded blooms with your fingers. This action redirects the plant’s energy from seed production to developing new flowers.
To encourage bushier growth and prevent legginess, perform a general cutback. This involves reducing the plant’s overall size by approximately one-quarter to one-third of its height. When making cuts, aim to snip just above a leaf node or a new bud, as these are points where new growth will emerge. For perennial varieties, the most intense pruning occurs in early spring, where old, woody stems are cut back significantly, often down to about 2 inches from the ground or just above new green shoots. This rejuvenates the plant and promotes a strong, full habit. Regularly removing any diseased or brown, drooping foliage also contributes to the plant’s health and appearance.
Caring for Verbena After Pruning
After pruning, adequate care helps verbena recover quickly and promotes robust new growth. Immediately after trimming, water the plant thoroughly, ensuring the soil is consistently moist but not waterlogged. This supports the energy required for new development. Verbena prefers well-draining soil and can tolerate some drought once established, but consistent moisture is important following a cutback.
Consider applying a balanced, slow-release fertilizer after pruning, especially if the plant needs a boost or if you performed a significant cutback. For container-grown verbena, a water-soluble fertilizer can be applied monthly to support continuous flowering. Monitor the plant closely for any signs of stress, such as wilting or discolored leaves, and address potential issues like pests or diseases promptly. Adequate sunlight, 6-8 hours of full sun daily, remains important for vigorous growth and abundant blooms after pruning.