Daylilies grow from an underground root system that is similar to a bulb. While the roots of existing daylilies can be divided every three years for more plants, you can add additional daylilies to your garden by planting them from seed. Daylilies produce viable seed every year and saving your own is an inexpensive way to propagate your lilies. Seeds are also available for purchase from garden centers and seed suppliers.
Sow daylily seeds ¼ inch deep in a seed-starting flat that is filled with a sterile potting mix. Use a soilless potting mix containing vermiculite or peat moss as these provide optimum drainage. Space the seeds 2 inches apart in all directions, or sow one seed per section in divided flats.
Water the potting mixture from the top until the excess moisture just begins to drain from the bottom of the flat. Cover the flat with a piece of plastic wrap, which helps retain the moisture in the potting mixture during germination.
Place the flat in a brightly lit area that does not receive direct sunlight. Seeds germinate in approximately two weeks, according to the University of Georgia Extension.
Remove the plastic wrap once the first sprouts begin to emerge. Leave the seedlings in the brightly lit area and water them when the soil surface begins to feel dry.
Fill individual 3-inch diameter pots with the potting mixture. Transplant the daylilies to their own pots once they are 4 inches tall. Lift the daylily plant from the flat by its top leaves and plant it in the pot at the same depth it was growing at in the flat.