Care for GRASSES

With grasses, knowing what to do when can be confusing. But it’s easy once you’ve established which are deciduous and which are evergreen

February is the perfect time to make a start on cutting back deciduous grasses. Many popular garden grasses are deciduous, such as miscanthus, Calamagrostis x acutiflora ‘Karl Foerster’, deschampsia, molinia, and pennisetum.

Most of these grasses are left to stand over winter because their weathered, beige- and biscuit-coloured stems and ornamental seedheads put on such a long-lasting display. But by February or March even the most decorative grasses start to flag, and their old leaves and stems need to be cut back to the base just before new shoots emerge. Cut back any later and you risk damaging the fresh spring growth. Use secateurs, shears or even an electric hedge trimmer if you have lots of grasses to prune.

Some deciduous grasses such as Pennisetum orientale (below) start into growth quite a bit later than others. These plants’ old stems should be left in place for longer to protect the crown, before being cut back around late April.

As for semi-evergreen grasses like Stipa tenuissima, evergreen species such as festuca and the sedges carex and luzula, these don’t need to be cut back at all. Simply use a hand fork, lawn rake or a gloved hand to gently pull out dead leaves from the base.

Pampas grass ( Cortaderia selloana) is one evergreen grass that does benefit from being cut back in early spring. Be sure to wear thick gauntlets and protect your eyes though, since its leaves are razor sharp.