Ask Anne!
Dividing your perennials
Q To fill empty spaces in the garden, I plan to divide some large clumps of perennials. Is spring or autumn the best time to do this – and when making large groups, how many plants per metre should I use?
Sam Muirhead, Nether Heyford, Northampton
Hardy herbaceous perennials, Michaelmas daisies and , are plants that die back in winter and grow again in spring. Versatile and long-lived, they eventually spread into large clumps with all the healthy flowering growth around the outside and a bare patch in the middle. Fortunately, these perennials take kindly to being forked up (usually while dormant), divided into chunks and replanted. This is good news when you have spaces to fill, especially as larger swathes and repetitions of favourites like hardy geraniums, agapanthus and daylilies are easy on the eye.
