Divide Perennials to Keep Them Healthy
Many perennial plants benefit from being divided every two to five years. If yours are starting to look crowded, overgrown, or are not flowering as well as they used to, or you would like to increase the numbers of a perennial, it might be time to divide. Tricia shows how she divides perennials in her yard in our video, Dividing Perennials. Most perennials can be divided any time of the year. However, you will have the best success in spring or fall for summer-flowering plants, or in late summer for spring-flowering plants. Basically divide the plant after it has flowered. Try to avoid dividing during the hottest part of the summer, and also no less than 6 weeks before the first frost, so that your divisions are not stressed by extreme temperatures while they re-establish their roots.