How to Divide and Plant Perennials

Adding perennials to your garden is an affordable, easy way to increase structure, color, and variety in your landscape. A perennial plant, as defined by The Free Dictionary is a plant that is "living three years or more" without having to reseed or replant. There is a vast array of perennials to choose from, in every shape, color, and size that you can imagine. They are low maintenance, and if chosen properly for your climate, will provide years of enjoyment. Plants can be purchased through your local nursery or garden center, at local plant sales, or from neighbors and friends the next time they divide their collection. Perennials may also be started from seed indoors or sowed directly in the garden.

Some perennials are fast growing and will require more garden space, while others spread very slowly and are more compact. Generally the fast-growing plants should be divided every 2-3 years; and plants that spread more slowly should be divided every 3-5 years. If your garden is well watered and fertilized, it may be necessary to divide plants more frequently to avoid overcrowding. However, there are some plants that should not be divided, such as Baby's Breath and Balloon Flower, but these are typically not as prolific. For a complete guide to what plants can be divided, see this University of Minnesota guide.

Dividing perennials is done for a variety of reasons including overcrowding; to clear away dead or diseased roots; because the plant is no longer flowering; or just to propagate them. It is also a great way to rid the garden bed of invasive weeds.

According to The New Perennial Club, a good basic rule of thumb is that it is best to divide spring blooming perennials in the fall; and fall blooming perennials in the spring. This way they'll have plenty of time to regenerate before their next blooming season. If you are dividing plants in the fall, cut back the foliage before digging up the plant, to make them easier to handle.

In preparation for dividing your plants, water them thoroughly a day or two before you plan to dig them up. This will give them strength to get through the transplanting process as it can be traumatic for them. Also, have the hole for their new home dug so that you can plant them immediately after splitting them. This decreases shock to the root system. Recycled pots from the garden center, or plastic grocery bags work well for transporting plants, if you are giving them away.

Division of the plants can be done one of two ways. The first is to cut the root system apart, which can be done with the edge of a sharp shovel, or a knife. The second method is to slowly pull apart the roots to separate them.

To determine the best way to split a plant, dig the root system up by using a shovel to dig down into the ground, forming a circle around the plant. Once you've loosened the soil enough to lift the root ball, raise it out of the ground and place it on a level area (you may want to use a small piece of tarp or plastic to keep the dirt together). If the roots are large and dense, use a knife or spade to separate them. If they are small and string-like, work them apart with your fingers, or with two forks. Don't worry that you're being too hard on them, as most perennials are hardy and will not only survive, but will thrive after getting reestablished in their new home.

To ensure the success of the new plant, each section should have healthy roots with 2-3 shoots and should be planted at the same depth as the parent plant. Water the plants well for the first few weeks, and during dry spells to ensure the development of a strong root system. When dividing perennials in the fall, is it especially important that they receive plenty of water before the ground freezes so that they can survive through the cold winter months. You may also want to cover perennials with mulch for extra protection during the coldest period of the winter.

Many hardy perennials such as Peonies and Irises will last for years and can be handed down through generations. Proper care and an occasional replanting will result in a vibrant perennial garden that can be enjoyed for years to come, with plenty of healthy plants to share with friends, family, and fellow gardeners.