Does anyone know when best to cut back miscanthus sinensis malepartus to the ground to allow new growth in Spring?
I would leave the old growth on overwinter and remove it in Spring when the new growth appears.
A gardener's work is never at an end - (John Evelyn 1620-1706)
Vendée, Western France
The stalks and old flower heads look good in frosts and provide shelter for insects over winter so leave them until the first teeny green shoots appear at the base next spring and then cut all the old stems down to about 6" above ground and before the new shoots get that high or you'll lose their lovely points.
"We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw