How to Divide Perennials

Most perennials need dividing every two or three years anyway, which makes division one of the easiest ways to expand a garden for free — a single mature clump can often yield dozens of new plants.

When to Divide

The best window runs from late autumn through early spring, while plants are dormant. Many gardeners prefer to wait until after the coldest stretch, since perennials typically start shooting new growth again in January, making it easier to see exactly what you're working with.

How to Do It

Dig around the plant and lift the whole root ball, shaking off as much soil as you can to expose the buds around the crown. Pull the clump apart by hand where possible; a sharp knife or spade works for tougher root balls. Don't worry too much about precision — as long as each division keeps a piece of root attached to a piece of crown, it will almost always take. Get every division back into soil as soon as possible; if you have to wait a few days, keep them cool (a refrigerator works) so they don't dry out.