Muhly grass (Muhlenbergia capillaris) is an ornamental grass known for its airy, pinkish-purple plumes that emerge in autumn. This clumping perennial forms a mound of slender, dark green foliage, typically 2 to 3 feet tall and wide, with plumes reaching 5 feet. Pruning helps maintain its health and appearance.
Why Prune Muhly Grass
Pruning muhly grass benefits its health and appearance. Trimming encourages new, vigorous growth, keeping the plant full and vibrant. It also removes dead or damaged foliage, improving its look. Enhanced air circulation at the plant’s base helps deter debris buildup and reduces pest and disease issues.
When to Prune Muhly Grass
The best time to prune muhly grass is in late winter or early spring, just before new growth begins. This aligns with the plant’s dormant period, minimizing stress and allowing quick recovery as its active growing season starts. Pruning then ensures the plant directs energy into producing fresh foliage and its characteristic fall plumes.
How to Prune Muhly Grass
Pruning muhly grass requires a few basic tools and a straightforward technique. You will need sharp bypass pruners, grass shears, or hedge shears for clean cuts. Wearing sturdy gardening gloves is advisable to protect your hands from the prickly grass blades.
First, gather the upright foliage into a manageable bundle. Tying the grass clump with twine or garden tape can make cutting easier. Once bundled, use your tool to cut the entire clump back to 2 to 6 inches above the ground. This removes old, dead growth and prepares the plant for new greenery. Clean, decisive cuts promote healthier regrowth.
Post-Pruning Care and Tips
After pruning, clear all cut material from around the plant’s base. This reduces pest and disease hiding spots and improves air circulation. While established muhly grass is drought-tolerant, water newly pruned plants to support initial regrowth, especially if rainfall is scarce.
Mulching with a 1-2 inch layer of bark mulch conserves soil moisture and protects roots from temperature fluctuations. Fertilization is generally not required for this low-maintenance grass. However, if your plant struggles or has stunted growth, apply a balanced, slow-release fertilizer in late winter or early spring. Avoid pruning muhly grass in mid-to-late summer, as this disrupts its fall plume formation.