7 Perennials to Divide in the Fall

Dividing Plants

Dividing plants is good for the look and health of your garden. Overcrowded plants compete for resources, and they’re more at risk for plant diseases. Dividing is also an easy way to get cheap plants. You can divide and replant in your yard, or give away the extras to friends and neighbors. To divide plants successfully, timing is important.

When to divide plants

“Plants that are stressed and need to be divided will show you signs that they need to be split up,” says Shelby DeVore, founder of Farminence. “They may bloom less, or have smaller blooms.  You might notice a ‘bald spot’ in the center of the plant. Or certain stems of the plant may need to be staked up in order to keep them from falling over.”

Dividing plants, like pruning, is a seasonal chore. The same rule of thumb applies: Divide spring-blooming plants in the fall and fall-blooming plants in the spring. But there’s another indicator of when to divide plants — their roots.

“Generally speaking, perennials that have a tuberous bulb should be divided in the spring,” DeVore says. “Plants that have fleshy roots can be divided in the fall.“

Most plants do not need to be divided every year. Some are best divided every few years; others can go for a decade or more before it’s time for a trim. It’s also best to divide plants on a cool, cloudy day to prevent the sun from drying them out.

How to divide perennials

To divide a plant, first dig up the entire plant. Then brush or shake off as much dirt as you can from the roots. “Most fall-dividing perennials can be easily pulled apart,” says DeVore. Use your hands or garden forks to separate the plants.

“For roots that are tough to break apart, you can use a spade or small hand saw to cut through them,” says DeVore. “It sounds aggressive, but you won’t cause any lasting damage to the plant by separating them this way.” Dividing plants in the spring tends to take more effort.

Once they are divided, plant them wherever you like. They can go back in the ground or into pots to be shared. Place them in rich soil and keep them watered — you may want to add soil amendments before replanting. When dividing plants in the fall, DeVore says, “make sure that your plants have at least six weeks to grow before your first average frost date.”

Here are seven perennials to divide in the fall and five to leave until spring.