Daylilies are beautiful, hardy plants that can survive the winter in all but the coldest climates. Many gardeners who live in zone 5 and below choose to dig up their daylily bulbs to ensure that they survive the winter. Even if you are fairly sure that your daylily bulbs will survive, winter digging is a great time to weed out unviable bulbs and divide viable ones for re-planting next spring.
Daylilies are ready to dig as soon as the first hard frost has killed or damaged its foliage. Use your trowel to loosen the soil at least 6 inches away from the base of the daylily. Loosen the soil in a circle around the daylily until the bulb can easily be pulled out of the ground.
Compost any damaged, diseased, or markedly smaller daylilies.
Clean the soil off of the bulb by running it under a stream of luke warm water. Then gently wipe it off.
Cut the foliage back to 4 inches above the bulb.
Allow the daylily bulbs to dry for three days in a cool, dark place indoors.
Line the box with a 2 inch layer of peat moss. Lay the daylily bulbs on top of the peat moss. None of them should touch. If you must stack bulbs, be sure that there is an ample amount of peat moss between layers. Do not stack them more than three bulbs high. Cover the top bulbs with another 2 inch layer of peat moss.
Store the packed bulbs in a dark, well-ventilated place that is roughly 40 degrees F, the crisper section of the refrigerator works well.
Periodically check on them to make sure that none are rotting or molding (these bulbs should be removed and composted immediately). If the bulbs are too dry, sprinkle the peat moss with water.