If you're talking about true grasses, such as the miscanthus and pennesitum you mention, cut back late winter/very early spring, before growth begins, so depending where you live and whether we're suffering arctic conditions at the time, I'd interpret that as last week of February, first week of March (here in London). True grasses from cooler regions start producing growth during late winter, but other grasses don't start till early to mid spring, so there can be differences in when growth starts depending on variety. This info doesn't necessarily apply to sedges and rushes - they generally get lumped under the description 'grasses' even though they're not really.

Depends too, on how many you have. I am beginning ours now and it will take until the end of April to do them all.

Thanks to you both. I dont have many so will hang fire until end feb. cheers.

Spring is also the time to divide and replant or propagate the deciduous types of grasses, when you see the new growth appearing, it is a sign that the roots are becoming active again.

thanks owdboggy.