I’m sure you have heard that perennials should be divided, but what does that mean? How do you do it? And when? With a few guidelines, you’ll be a pro at this simple garden task.

Division is one of the best ways to multiply the number of plants in your garden and, better yet, it’s free! The process is quite simple. Just dig up a perennial that has gotten too large, cut the root mass into smaller sections, space these new plant pieces farther apart and replant them in the garden. You don’t have to be delicate about this either. Just cut through the root mass with a sharp spade, being careful not to make the sections too small. Each section needs enough root mass itself to be viable. Be sure to water well any perennials you are planning to divide a day or two before doing the division. This will lessen the stress on the plants during and immediately after division. And, of course, water well a couple of times a week for a few weeks after replanting your divisions.

Dividing perennials will rejuvenate those that have become less vigorous or are blooming less than they used to because they’ve gotten too crowded. A good rule of thumb is to divide perennials every 3-5 years, making each new section about a quarter of the original.

In general, spring and summer-blooming perennials should be divided in the early fall. Fall-blooming perennials should be divided in early spring. One exception to this is the division of irises. This should be done in early to mid-summer after they finish blooming.

If you find that you end up with more than you need of any one plant, your gardening friends might be very happy to receive some of your divisions for their gardens. They may even trade you some of their divisions as well!