A perennial garden gives you a repeat performance of beautiful flowers, year after year. Keep the show going strong by dividing your perennials in the spring or fall. Perennials tend to spread out, with new plants jostling for nutrients and water. They choke one another out as they compete for resources. Dividing your plants keeps them healthy and beautiful.
Some perennials are slow and steady growers. Others, such as yarrow or black-eyed Susans, are speed demons. You need to divide the fast growers just to keep them from taking over your garden. Divide spring and summer blooming perennials in the fall, and fall blooming plants in the spring.
Dividing proven performers and replanting them keeps more money in your pocket. You can even trade your divided plants with your neighbors to add a little variety at no cost.
When your perennials get too big, they put more energy into grabbing resources rather than producing beautiful flowers. Dividing them gives them room to grow and helps with circulation. When you run out of room for replanting, give flower starters to your friends and let them share the beauty you've cultivated.