Q When’s the best time to divide my ornamental grasses? Mr B Wilson, by email A Ornamental grasses are best divided in spring, when they’ll grow away well. Divided in autumn, they can often sit and sulk in a wet, cold soil. If the foliage is getting in the way, it can be cut back, but not too far because it helps protect the crown of the plant over winter. Depending on the grass and its toughness, either use forks back-to-back to divide the clumps or an old bread knife.
Leave it a few months before spli ing up grasses