The Rams Horn Willow (Salix babylonica ‘Crispa’) is a distinctive deciduous tree celebrated for its unique, ornamental features. This cultivar is prized in landscapes for its dramatically twisted branches, which provide a compelling structural focal point, especially in winter when the leaves have fallen. Its common name comes from its unusual foliage, where each leaf is tightly curled and spiraled, appearing much like a ram’s horn. The attractive, contorted stems are highly sought after by florists and crafters for use in arrangements.
Site Requirements and Initial Planting
Selecting the proper location is important for the long-term health of a Rams Horn Willow. The tree performs best in full sun (at least six hours of direct sunlight daily), though it tolerates partial shade. While not particular about soil composition (clay, loam, or sand), it requires consistently moist conditions.
Willows thrive in deep, rich soil that is well-draining or somewhat wet. When planting, dig a hole two to three times the width of the root ball. Place the tree so the top of the root ball is slightly above the surrounding grade, and backfill with the excavated soil, ensuring no air pockets remain.
The tree can reach 30 to 40 feet tall, requiring careful consideration of its proximity to structures. Like other willows, it develops a shallow, extensive root system. Plant it a safe distance away from house foundations, walkways, driveways, utility lines, or plumbing to prevent damage.
Essential Routine Maintenance
Consistent and adequate irrigation is the most demanding aspect of care. These trees require a high volume of water and should never be allowed to completely dry out. Watering generously and regularly during the first year is necessary for the tree to develop a robust root system.
Applying a two to three-inch layer of mulch around the base of the tree helps conserve soil moisture and moderates temperature. Keep the mulch several inches away from the trunk to prevent moisture accumulation that can encourage pests or disease. Once established, the tree still needs supplemental water during prolonged dry or hot periods.
Fertilization is minimal, as excessive feeding can lead to weak, overly rapid growth. If the tree appears to be struggling, apply a balanced, slow-release fertilizer in the spring. Monitor the tree for common issues, including fungal diseases like anthracnose, rust, and cankers, and pests such as aphids and borers. Promptly removing dead, diseased, or damaged material helps maintain the tree’s health.
Pruning for Desired Form
Pruning maintains the ornamental value and overall health of the Rams Horn Willow. The primary goal is to encourage the distinctive contorted new growth and manage the tree’s size. The best time for major pruning is in late winter or early spring while the tree is dormant.
Start by removing any dead, broken, or crossing branches. Also remove straight, non-twisted shoots (suckers) that emerge from the trunk or rootstock. Cut suckers cleanly back to their point of origin to prevent them from dominating the tree’s growth. Thinning the canopy encourages good air circulation and light penetration, which helps reduce the risk of disease.
To maximize the supply of curled stems, the tree can be managed through coppicing or pollarding. Coppicing involves cutting the entire tree down to a few inches above ground every few years, stimulating vigorous, highly contorted new shoots. Pollarding is a similar technique where branches are cut back to a permanent trunk or scaffold branches. These methods manage the tree’s size and ensure a continuous supply of intensely curled stems.
Propagation Methods
The Rams Horn Willow is simple to propagate. Contorted branches harvested during pruning can be converted into new plants. Propagation is most successful using hardwood cuttings (late fall/winter) or softwood cuttings (early summer).
Select healthy, one-year-old stems (half an inch in diameter) and cut them into 8- to 12-inch sections. Cuttings can be placed directly into water, where they root quickly, or inserted into moist soil. When planting in soil, ensure at least two nodes are buried beneath the surface. Keep the soil consistently moist until the cuttings develop a strong root system.