Daylilies are tough plants, easily grown and not too fussy about conditions. If you want abundant bloom, however, you need to give them the best conditions possible. In xeriscaping (from "xero," Greek for "dry") every effort is made to reduce the amount of water used, so make every drop count by preparing the soil and watering with care.
Dig a large quantity of organic matter such as peat moss, compost or steer manure into the ground before you plant your daylilies. Spread 2 to 4 inches of your material over the top of the ground, scatter 1/2 cup of bone meal per square yard over that, and mix thoroughly with the soil to a depth of at least 12 inches using a garden fork or shovel.
If you have the energy, remove the top 6 inches of soil, add your organic matter and bone meal and mix deeply. Then put the top 6 inches back, add another 2 inches of compost, peat moss or steer manure and mix again. Now you have 18 inches of good soil that will encourage roots to grow deeply, using the water you apply more effectively.
Plant your daylilies and water well. Spread mulch over the top of the ground, using ground bark, straw or other material. This top dressing keeps the soil cool and moist.
Apply more water whenever the soil feels dry in the top inch during the next two or three months, giving the plants time to get growing well before holding back on the water. Fertilize once with a 5-10-10 liquid fertilizer after a month. This formula helps grow sturdy roots and stems.
Water deeply and infrequently the first two years without letting the soil dry out more than 4 inches deep. This promotes deep root growth as the feeder roots search down for their water supply but will not stress the plants before they have a strong root system.
Water slightly more often in spring and early summer, the times when flower buds are forming and plants are growing strongly.
Apply enough water to soak the top 12 to 18 inches of soil whenever the top 6 inches of soil is dry during subsequent years. You'll have strong, tough plants that are drought-tolerant at this time, and you can neglect them a bit without damaging them. Again, apply more water in spring and early summer.