Propagating daylilies is almost as easy as it is to grow the plants. Division is the most common and efficient method to procure more plants, but growing daylilies from seed is also an option. Be aware that the daylilies you grow from seed will not be like the parent plant or each other. If you want more of a particular variety, division is the method to use. The optimum times to separate a daylily is in the early spring or fall when it is dormant, although division can be done successfully at any time. Growing daylilies from seed requires more of an exact time frame.
If you are planning to plant the divisions rather than give them away, choose areas in the sun or part shade where you would like to plant your divisions. Dig the areas and amend with compost.
Prune off any dead foliage remaining on your dormant plant. If you are dividing during the growing season, prune the foliage back to about 6 inches from the base of the plant.
Place a shovel several inches from the edge of the daylily clump and dig down approximately 12 inches to get under the root ball.
Lift the clump from the ground and lay it on its side.
Take the shovel and cut the clump into six or eight divisions, depending on the size of the clump.
Take the weeding fork and gently pull apart pieces from the larger sections, if you wish to have more divisions. Each division should have at least one fan of leaves and a section of healthy roots.
Water the divisions and place in the shade until you can plant them.
Dig a hole for each division approximately 6 inches deep and plant with the roots slightly spread. Backfill until the soil is just above the crown of the plant (just below the leaves and above where the roots begin). If you are planting the large sections, plant them about 2 feet apart, according to Suzy Bales, writing for This Old House online. The smaller divisions may be planted approximately a foot apart.
Water thoroughly. Water every day for a week, then water once a week if the weather is dry.
Let your daylily develop seed pods by not removing the old flowers or the stems after the flowering is finished.
Harvest the seeds when the pod begins to split open. According to the daylily website Bill's Hemerocallis, the seeds are ripe approximately 60 days from flowering.
Tap the seeds out into your hand and place in a zippered plastic bag. Refrigerate for four to six weeks.
Fill the pots with a seed-starting potting mix and plant the seeds 1/2 inch deep. Do this in September in warm climates and leave outside. In northern areas, bring the pots inside and grow them under lights or on a sunny windowsill that doesn't get too cold. Keep the soil moist.
Fertilize lightly with a balanced fertilizer after the seeds have sprouted and the seedlings have two sets of true leaves. Do not count the first set of the leaves.
Place the pots outside in the spring if you have grown them inside.
Transplant your daylilies into the ground when the plants are established. This may take two to three years.
Follow planting instruction in Section 1, Steps 8 and 9. Plant 12 inches apart.