Daylilies grow vigorously, and many new types bloom repeatedly all summer until frost. They multiply rapidly. When your daylily bed becomes crowded, divide the crowns and transplant them to other areas of your garden. Daylily divisions make good gifts for your gardening friends, or trade species with other growers to amass a wider variety in your garden.
How Often Should I Divide Daylilies?
Most standard daylilies need to be divided every three to five years. The closer together you space the crowns when you set them out, the more quickly they will fill the bed. Some species are naturally slower growing, and other conditions such as soil fertility and exposure to sunlight affect how quickly daylilies multiply. Many newer species, such as Stella d’Oro, are very fast growing and need to be divided every two or three years. Your daylilies need to be divided when you notice that the tubers form a mass, perhaps pushing above the soil surface, or that the plants are producing fewer leaves and flowers. It is a good idea to divide daylilies before they reach these extremes.
The Best Time of Day to Plant Daylilies
Dig your daylily divisions early in the morning. Avoid having the daylily crowns bare-root during the heat of the day, when they can easily become dried out. If you prepare the new planting bed the evening before you plan to replant the crowns, you can move the crowns quickly. When you replant them early in the morning, water them in and apply a layer of mulch before the hot sun gets to the tender roots. Once they are established, they will be as hardy and adaptable as they were before they were replanted.
Season of the Year for Transplanting Daylilies
Daylilies are hardy and robust, which makes them easy to divide and replant. Almost any time during the growing season is a good time to replant daylilies. Give the transplants plenty of time to establish new feeder roots before winter dormancy begins. Other than that, daylilies are forgiving plants that seldom have problems with transplant shock if proper planting methods are used.
Some growers recommend spring transplanting. In areas where the spring soil remains moist, new spring plants will require less watering and care. Spring-planted daylilies have the entire growing season to become established in their new home, and they will often bloom the first year if you are replanting large-sized divisions from mature plants.
Fall transplanting also has some advantages. If you want to mark specific colors or types of daylilies to replant, you can easily tag them when they bloom, and then move them later in the fall. When the weather has cooled some, there is less chance of transplant shock. In the fall, the newly planted crowns will put energy towards feeder root development as dormancy approaches, rather than trying to produce leaves and flowers.
Daylilies can also be successfully replanted in the summer. Give them extra attention. Provide plenty of mulch and ample water to offset the effects of summer heat, and summer planted daylilies will thrive.