Salix integra, commonly known as Dappled Willow or Hakuro Nishiki, is a deciduous shrub with distinctive foliage. Its leaves emerge in vibrant shades of pink, creamy white, and green during spring. As the season progresses, the pink hues may soften, but the variegation continues. Its graceful form and multi-seasonal interest make it a favored choice for ornamental landscapes.
Site Selection and Planting
Selecting the appropriate site is important for a healthy Dappled Willow. It thrives in full sun to partial shade; full sun enhances leaf coloration. While adaptable to various soil types, it performs best in moist, well-draining soil. Its natural habitat near rivers suggests a preference for consistent moisture, but proper drainage is necessary to prevent root issues.
When planting, allow about 2 meters (6 feet) for its growth. Mid-September to October is ideal for planting to allow root establishment before winter, though potted plants can be planted in spring. Dig a hole twice the width of the root ball and the same depth as the nursery pot. Incorporating compost or well-rotted manure helps enrich the planting site. After placing the plant, backfill with soil, gently firming it around the root ball, and water thoroughly to settle the soil.
Watering and Fertilizing
Consistent moisture is important for the Dappled Willow, as it dislikes dry conditions. Newly planted shrubs require regular watering to establish roots, and continued irrigation is necessary during dry spells. While the plant enjoys moist soil, ensure the ground remains well-drained to prevent waterlogging.
Applying a 5 cm (2 inch) layer of mulch around the base in spring conserves soil moisture and moderates soil temperature. This practice also provides a gradual release of nutrients as the mulch breaks down. For additional nourishment, a balanced, slow-release fertilizer can be applied in early spring before new growth begins. Fertilizing every 4-6 weeks during the growing season can support vibrant foliage, but avoid over-fertilization to prevent damage.
Pruning for Optimal Growth
Pruning is important for Salix integra to maintain its attractive form and encourage variegated foliage and colorful winter stems. The best time for major pruning is late winter or early spring, typically March, before new growth emerges. This annual pruning encourages vigorous new shoots, which display the most intense variegation. For standard forms, remove any shoots that sprout from the main stem below the grafted head.
When pruning a bush form, cut back about one-third of the growth to promote lush foliage. For rejuvenation, established shrubs can be cut back to about 60 cm (2 feet) in height; this stimulates a robust flush of new growth. Throughout the season, remove any dead, damaged, or crossing branches to maintain the plant’s health and shape. A light trim in July can encourage a second flush of desirable foliage. Delay the first pruning until the second spring after planting, allowing the shrub to establish a strong root system.
Pest, Disease, and Common Problems
Salix integra is generally resilient, but can encounter common issues. Pests such as aphids, spider mites, leaf beetles, and sawflies may affect the plant. While chemical solutions are available, non-chemical approaches like dislodging pests with a strong spray of water can manage minor infestations. Regularly inspecting foliage helps in early detection and control of pest activity.
Diseases like powdery mildew, canker, and rust can occur. Good air circulation around the plant helps prevent fungal issues like powdery mildew. If rust appears as rusty patches on leaves, picking off affected leaves can limit its spread. Physiological problems, such as leaves losing variegation or turning yellow, often relate to environmental factors. Loss of variegation can result from insufficient sunlight, while yellowing leaves or browning tips may indicate too much or too little water, necessitating an adjustment in watering practices.
Winter Protection
Salix integra demonstrates good cold hardiness, thriving in USDA hardiness zones 4 to 9. In most regions within these zones, established plants require minimal winter protection beyond natural dormancy. The stems of new growth will develop a coral-red hue in winter, providing seasonal interest.
For ground-planted Dappled Willows, applying a layer of mulch around the base provides additional insulation for roots and helps retain soil moisture during colder months. If grown in a container, it benefits from extra protection due to the exposed root system. Containerized plants should have their pots wrapped in insulating material like burlap or fleece, and can be moved to a sheltered location, such as against a building or in an unheated garage, to guard against severe cold. During dormancy, reduce watering, ensuring the soil is not waterlogged, which can harm roots in freezing temperatures.