I have a large number of miscanthus, molinias and pennisetums. I love them all - but they're looking very tatty - and I'm dying to cut them down! Some experts say "do it in February before the new growth starts, so you don't damage anything". Others say "Leave it until March. It doesn't matter if you cut some of the new growth off". We live in Dorset: would it be totally stupid to do it now?