One of the many blessings of perennial plants is their ability to spread and be divided, providing new flower clumps to plant elsewhere in your garden. Unlike annuals that need to be purchased and replaced every year, perennials are the gift that keeps on giving. When it comes to dividing perennials, generally speaking, any plant that blooms after mid June is best divided in the spring. Flowers that bloom in early spring are best divided in the fall.
Steps for Dividing Perennials
- Once you see a growth of one to two inches in the spring, dig up the entire plant, getting as many roots as possible.
- Place the plant on a tarp or in a large plastic bin (like a shallow storage box) where you’ll separate it.
- Knock off as much loose soil as possible from the roots. You can gently knock the clump against the tarp, use your hands to shake off excess dirt, or even use a garden hose on a stream setting.
- Using a paring or garden knife (even a steak knife will do), cut the plant in two. Sometimes you’ll be able to see a divide in the roots where the plant can be easily separated. But if not, simply cut through the roots vertically to make your separation.
- If your plant clump is large, you can repeat step 4 to create more plantings for your garden. Each piece should be about the size of your fist and should include both roots and above ground growth.
- Plant the divided perennials into new locations at the same depth as when you removed the plant. You can place a section back into the original growing location.
- Water the divided perennial after planting, and then water once weekly (if it doesn’t rain) for the first month.
- If you have more divisions than you need, give some to friends and neighbors.
Don’t be alarmed if a couple of your transplants don’t survive. This happens from time to time, although I can’t remember any of my divided perennials not making it. I find it so rewarding to create new gardens from existing plants; there’s a special pride in getting new flowers for free!
Types of Perennials to Divide in Spring
Not sure which plants are candidates for dividing in the spring? Here’s a list of some of the more common plants you can divide now, although this list is not comprehensive. Just remember the general rule of thumb: in the spring you can divide perennials that don’t bloom until after mid-June. Otherwise, wait until fall.
- Astilbe, divide every 2-3 years
- Bee balm
- Black-eyed Susan, divide every 3-4 years
- Blanket flower, divide every 3-4 years
- Coneflower, divide every 4-5 years
- Daylily, divide every 4-5 years
- Delphinium, divide every 2-3 years
- Garden mum, divide every 2-3 years
- Lady’s mantel, divide in spring or fall
- Salvia, divide every 5-6 years
- Shasta daisy
- Speedwell (Veronica hybrids)
- Yarrow, divide every 2-3 years