The plants' foliage looked stunning in winter's early morning light at a time of year when much of the garden was asleep.
Leaving the foliage on over winter also protects the plants from cold and moisture, minimising the chance of winter rot; but now it’s time to cut them back, as they’re starting to look unkempt.
This job is done in various ways. I comb out the dead leaves on the evergreen entries, including Stipa tenuissima, with a spring-tine rake starting at the bottom and pulling upwards.
On the deciduous entries, including S. ambigua and S. formicarum, I cut the old dead leaves back to just above new growth using secateurs - you can also use shears - into a slightly mounded shape about 30cm (1ft) high. Then I rake out any remaining dead leaves. For the evergreen S. gigantea entries I cut down their long oat-like flower stems, measure them for the trial, and comb out the dead leaves.
After this I hoe the bed and cultivate the soil to remove my footprints and improve the drainage (Stipa don’t like it wet). The end result is a neat bed ready for this season’s growth - and another year to perform. Stipas are mostly clump-forming, cool season evergreen grasses, needing full sun and well-drained soil that is not too fertile.
Come and visit the trial in the autumn to see them at their peak.
Find out more about RHS Plant Trials
RHS advice: Ornamental grasses
RHS advice: Cutting back ornamental grasses