Pruning Feather Grass
When and how — Stipa tenuissima
Prune your feather Grass in March — the optimal month is usually March.
The next pruning window is March next year.
When to prune?
The ornamental grass feather Grass is pruned in March.
Cut ornamental grasses once a year, at exactly the right moment.
Ornamental grasses split into two groups with very different needs. Warm-season grasses (Miscanthus, Panicum, Pennisetum) die back above ground over winter and are cut down to about a fist's height in February or March. Those dry stems provide winter interest and protect the crown from frost and rain. Cool-season grasses (Stipa, Carex, Festuca, Deschampsia) stay green or semi-evergreen and must NOT be cut back hard — a spring tidy where you comb out the old dead blades with gloved hands is enough. Hard-prune a Stipa and whole tufts can rot out and die.
How to prune feather Grass
Feather grass requires minimal pruning, but an annual tidy-up in March keeps plants looking their best and encourages fresh, vigorous growth. Unlike many ornamental grasses that are cut back hard in late winter, Stipa tenuissima benefits from being left standing through autumn and winter. The bleached, straw-coloured foliage and seedheads provide valuable structure and movement in the dormant garden, and the old growth offers some frost protection to the crown. In March, before new shoots emerge, use a pair of sharp garden shears or secateurs to cut the entire clump back to within 5–10 cm of the ground. Work carefully to avoid damaging the crown or any emerging green shoots at the base. If you prefer, you can simply comb through the clump with gloved hands or a rake to pull out dead material, though a full cut-back is quicker and neater. Dispose of the trimmings on the compost heap or in green waste—do not leave them around the base, as they can harbour slugs and encourage rot. Feather grass is short-lived compared to many perennials, often declining after three to five years. If your clump looks sparse or dies out in patches, it's usually a sign the plant has reached the end of its natural lifespan rather than a pruning issue. Self-sown seedlings often appear nearby and can be transplanted to replace older plants. Deadheading is unnecessary and removes much of the ornamental appeal, so allow the feathery seedheads to develop and persist through summer and autumn.
Common mistakes
✗ Cutting warm-season grasses down in October
You lose the winter silhouette AND the crown drowns without the protective dry stems. Wait until late February or early March, just before new growth starts.
✗ Hard-cutting cool-season grasses
Species like Stipa tenuissima and Festuca tolerate it poorly and may rot out. Combing with gloves is the right approach.
Too late this year? Here's what to do
Better to wait than prune at the wrong moment. The next optimal window is March next year. Until then: leave the plant alone — only remove dead or diseased wood (which you can do year-round).
