Perennial flowers are a great addition to the garden. You don’t have to plant them new every year and every year they grow larger and produce more and more blooms. Eventually the number of flowers they produce becomes less and less. When that happens, it’s time to dig them up and divide them.
The best time to divide perennials is just after they finish blooming. In other words, divide spring-blooming perennials in late spring or early summer. Divide summer-blooming perennials as soon as they finish blooming, and divide fall-blooming perennials in spring.
Some varieties of perennial flowers are easy to dig up and divide, others take a little work to both dig up and to separate their roots. Arm yourself with a sharp garden spade and a sharp pair of garden trimmers. Here’s how to do it:
- Trim the foliage back so it is about 1/3 of its former size.
- Starting about 1 1/2 to 2 feet away from its center, drive the spade into the soil in a ring around the entire plant. This will sever any wandering roots and make it somewhat easier to remove the plant from the ground.
- Go back around the plant, driving the spade even deeper into the soil on this round. Grasp the spade by the end of its handle and use leverage to rock the spade back and forth. This will help loosen the root ball from the soil.
- Repeat this one more time, for a total of three rounds of driving the spade into the soil in a ring around the plant.
- At this point, try to lift the plant with your hands. If it won’t budge, keep driving the shovel into the soil and try to angle it so that it goes underneath the plant.
- Once the plant is loosened from the soil, remove it from its planting site. If you can, shake off any loose soil.
- Set the root ball on a hard surface. Using the sharp spade, drive it through the root ball from the top to separate it. Continue separating each division into smaller and smaller units until the divisions are the size you desire. A good rule of thumb is that the new divisions should be not more than 1/4 the size of the root ball you started out with.
- Some perennials send out new growth at the edges of their root ball and the center of it dies off. If this is the case with the plant you’re dividing, then cut off the new growth at the edges and discard the dying center.
- Replant your new, smaller divisions. This is a good time to expand your garden or offer free plants to friends or neighbors.
Most perennials need to be divided every 3 to 4 years, although some will grow for many years–even decades–before needing to be divided.
Copyright Sharon Sweeny, 2009. All rights reserved.
Photo. Brenda Timmermans