Daylilies have been called the ‘perfect perennial’. They will grow in almost any type of soil from clay to sand. They are hardy, resistant to most disease and pests. The following are general guidelines which should give you the best results.
Daylilies bloom best in full sun. They will tolerate partial shade, but at least six hours of direct sun per day is preferred. Darker colors may benefit from partial shade during the hottest part of the day.
The area where you intend to plant your daylilies should be worked into a good loose condition as deeply as you can, preferably to a depth of at least 12”. Amendments such as well composted organic material should be mixed thoroughly with the soil. Raised beds may be constructed using landscape timber or treated wood, then filled with suitable potting mixes.
Generally, when planting, plants should be spaced 18 to 24 inches apart. Some cultivars multiply very fast, and you clumps will soon become crowded if planted too close together.
Prepare the plant by dividing into two to three fan groups. Trim foliage to a length of 6-8 inches for easier handling. Dig a hole slightly larger than the root mass. Make a mound in the center of the hole. The mound should be high enough to bring the crown of the plant to ground level. Set the daylly in place with the roots spread around the mound. Work loose soil around and between the roots as you cover the plant. Firm the soil, eliminating air pockets, then water well. After the initial soaking, it is best to not water again for several days to allow time for the formation of the small roots which will absorb the moisture.
CARE AND FEEDING
Daylilies are relatively drought tolerant, but perform best with adequate watering. The equivalent of one inch of rain per week is the optimum.
The type and quantity of fertilizer required is dependent on the conditions in your garden. A soil test is the most accurate way to determine your needs. In general, consider a 10-10-10 fertilizer in spring, and a lower nitrogen fertilizer such as 3-12-12 in the fall. Older clumps should be fertilized more heavily than newer plantings.
Although not essential, mulching is very helpful in improving soil, retaining moisture and weed control. Care should be taken when mulching to not cover the crown of the plant, as this can lead to rot.
Pre-emergent herbicides may be applied if you are not growing from seed. Layers of newspaper, covered with mulch, can also be effective for weed control.
Daylilies increase by developing additional fans. As the clumps mature, they may need to be divided. Substantial increase in the size of a clump may decrease the productivity of blooms as the fans compete for the available nutrients. When dividing, dig up the entire clump. Trim the foliage to a 6-8” length for easier handling. Washing the root mass will usually make the task easier. Gentle twisting and pulling will usually separate the fans, although in some cases it may be necessary to cut the fans apart using a sharp knife. If cut, it is advisable to apply a sulfur compound to the cut areas prior to replanting.