When it comes to foolproof perennials for sunny garden spots, few plants can beat the cheerful daylily. The plants are as tough as nails, shrugging off all insect pests and diseases, and some varieties (think of the ubiquitous 'Stella D'Oro') have bloom times that stretch into four months long. Daylilies have the added characteristic of growing ever-expanding clumps each year, giving the gardener more plants to populate the landscape or share with friends and family. For gardeners new to transplanting and dividing plants, the daylily is a most forgiving specimen for learning these techniques.
Why Transplant Daylilies?
It's so satisfying to see a daylily patch growing ever larger and more vigorous, throwing out new flower stalks each morning for weeks or months on end. However, as daylilies expand, their root systems become crowded, competing for limited nutrients and water in the surrounding soil. The above-ground foliage also becomes crowded, casting shade on itself and obscuring flowers in the center of large fans of leaves.
When you dig and divide daylilies, you break an overgrown clump into smaller plants, which rejuvenates them by reducing competition for sun, water, and nutrients. Moving daylilies also gives you an opportunity to place them in site with better sunlight or soil if the original planting stands in the shadow of a tree or shrub that has matured. Finally, transplanting daylilies allows you to move treasured varieties to another location entirely, if you want to share with friends or if you are moving. It isn't unheard of to find unusual daylilies listed for twenty dollars or more in catalogs, so taking plants with you to start a new flowerbed is a resourceful move for the budget-minded 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, cool soil temperatures and gentle spring rains help newly divided or moved plants to recover from transplant shock. Although exact timing isn't critical, attacking your transplant 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 7 and higher) can transplant daylilies in the fall as well. Wait until the end of September, when the heatwaves of summer have ceased.
Prepare to Transplant Daylilies
Before you transplant your daylilies, take a day to choose and prepare the new planting site. Plants need at least six hours of full sun to produce flowers. For red or purple varieties, some afternoon shade is desirable to avoid scorching of blooms. Work some compost into the soil, loosening it to a depth of 12 inches.
Carefully dig around the established clump of daylilies. Remove as much soil as needed with the rootball to preserve roots; you will knock this soil away as you determine how many divisions to make.
Remove soil with your hands and with a hose until you can visualize where each fan of foliage joins the root system. Aim for a division of three fans per division. Use a clean sharp garden knife (like the Japanese hori hori) to slice through the roots. Place your divisions in a shady spot and allow the knife wounds to air dry as you work.
Time to Replant the Daylily
You should now have loose, amended soil in your replanting site. Dig a hole slightly larger than your root ball. Pile some native soil mixed with compost in the center of the hole, and arrange the roots over this mound. The point where the leaves join the roots (the crown) should be at the level of the surrounding soil. Carefully fill in the hole, pressing away any air pockets. Water the transplant with compost or manure tea, soaking thoroughly.
Caring for Daylilies After Transplanting
Now that you've successfully dug and transplanted your daylilies, you must begin caring for them as if they were new plants you just installed in your garden. 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 newly planted 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 also encourage transplants to form deep root systems. Watering at the base of plants, rather than overhead, will reduce the chance of fungal diseases like daylily rust.
Remove weeds that compete for nutrients and water. You can use a combination of pulling, hoeing, and mulching to reduce weeds. Keeping daylily beds weed free also denies insect pests like slugs and thrips a place to hide and reproduce. Before long, your new plants will be putting up new scapes and flower buds in the garden.