When it comes to foolproof perennials for sunny garden spots, few plants can beat the cheerful daylily. Daylilies are as tough as nails, shrugging off many insect pests and diseases, and some varieties (think of the ubiquitous 'Stella D'Oro') have bloom times that stretch four months long.
Daylilies have the added benefit of increasing clump size each year, providing gardeners with divisions to plant in other areas of the garden or to share with friends and family. For gardeners new to transplanting and dividing plants, the daylily is a most-forgiving specimen.
Why Divide and Transplant Daylilies?
It's so satisfying to see a daylily patch growing ever larger and more vigorous year after year. For weeks on end, the plants push up new flower scapes and every morning a new bloom or two opens. However, as daylily plants mature, their root systems become over-crowded, competing for sunlight, soil nutrients, and moisture. The above-ground foliage becomes crowded, casting shade on itself and obscuring blooms in the center of large fans of leaves.
When you dig and divide a daylily, you are breaking up an overgrown clump into smaller plants, which not only creates more plants to increase your collection, it rejuvenates each plant to produce more blooms the following season.
Transplanting daylilies to a new location provides an opportunity to plant them in a site with better sunlight or soil if the original planting site was not ideal. You can move treasured varieties to another area of your garden or share them with a friend. It isn't unheard of to pay upwards of 20 dollars per plant for new or unusual daylily hybrids, so sharing your plants to start a new flowerbed is a resourceful move for a budget-wise gardener.
When to Transplant Daylilies
In all climates, the best time to transplant daylilies is in the spring when the shoots are just beginning to emerge. During this time, cooler temperatures and gentle spring rains help newly divided and transplanted plants to recover from transplant shock. Although exact timing isn't critical, transplanting earlier rather than later increases the chances that the plants will be able to recover enough to bloom later in the season.
Gardeners in the South (USDA growing zones 8 and higher) can transplant daylilies in the fall as well. Wait until the end of September, when the heatwaves of summer have ceased.
How to Dig and Divide
Before you dig and divide your plants, choose and prepare the new planting site. Daylilies need at least six to eight hours of full sun to produce flowers. For red or purple varieties, some afternoon shade is desirable to avoid fading and scorching blooms. Mix some compost into the soil, loosening soil to a depth of 12 inches.
Carefully dig around the established daylily clump and remove the plant from the ground. Examine the clump to determine how many divisions to make.
Brush or tease away excess soil with your hands or with a hose until you can visualize the logical points at which to cut apart the daylily clump. Use a clean sharp garden knife (like the Japanese hori hori) to slice through the fleshy root system. It's okay if your knife slices a fleshy root in half, the plant will survive. Place your divisions in a shady spot and allow the knife wounds to air dry as you work.
Time to Replant the Daylily
Dig a hole slightly larger than the daylily division root ball. Make a mound of native soil mixed with compost in the center of the planting hole, and arrange the roots over this mound. The point where the leaves join the roots (the crown) should be at the same depth as the surrounding soil; do not plant too deep. Carefully fill in the hole with soil, pressing away any air pockets. Water the transplant thoroughly to get it off to a good start.
Caring for Daylilies After Transplanting
Now that you've successfully dug and transplanted your daylily divisions, begin caring for them as if they were brand new plants. Any plant that is wrenched from its stronghold in the soil, is exposed to drying winds, and suffers root injury is going to need a little TLC to return to its full glory.
Consistent watering is the most important element to achieving a healthy daylily. Daylilies need adequate irrigation in the spring to form new buds, and a deep drink that soaks eight to ten inches into the soil will encourage transplants to form healthy root systems. Water at the base of plants, rather than overhead, to reduce the chance of wet foliage encouraging fungal diseases like daylily rust.
Use a balanced liquid or granular fertilizer to feed the plants about two weeks after transplanting as they begin to show signs of new growth.
During the growing season, use a combination of hand pulling, hoeing, and mulching to remove weeds that compete for sunlight, soil nutrients, and water. Keeping daylily beds weed-free also denies insect pests like slugs and thrips a place to hide and reproduce.
Before long, your new daylily plants will be lush, green and pushing up new scapes and flower buds.