In early spring, before growth starts, remove the dead foliage from the previous year’s growth and any weeds. A summer mulch helps to reduce the task of weeding. Perennial grasses can be difficult to eradicate if they become established within the clumps.
Although day lilies tolerate drought, they perform best in moist, but well-drained soils.
One inch of water weekly is ideal, more frequent watering may be necessary on sandy soils.
Remove seed pods after bloom to prevent seed production. Plants producing seed are likely to have fewer flowers the following year.
Insect control measures usually are not necessary. Aphids sometimes feed on the flower buds. These pests can be controlled with insecticidal soaps or a repeated strong spray of water.
Annual fertilization may be helpful in producing more flowers. A spring application of manure or compost is beneficial each year.
Cultivars
More than 35,000 daylilies have been named, officially registered, and marketed. Many newly developed plants are introduced annually.
Daylilies were traditionally plants that stopped growing and became dormant throughout the winter, but today there are semi-evergreen and evergreen cultivars.
Established daylily clumps often produce 200–400 flowers in a season. Bloom time extends from early to late summer. Each plant blooms for 30–40 days. With the large number of cultivars available, it is possible to have continuous bloom throughout the summer.
Daylily flowers come in many colours, shades, and colour combinations.
Some are very full and round, others have wide petals with ruffled edges and borders. Others are spidery in shape; doubles have double the number of petals and sepals.
Day lilies are regional performers which means they grow well only in certain parts of the country. For this reason, you should purchase daylilies from a local nursery.