Caring for Daylilies

A wealth of information regarding Daylilies can be found in our Forum.
 

General Care:
For the best quality flowers, daylilies should be grown in full sun, however they will tolerate light shade. But generally produce fewer blooms grown in partial sun. Daylilies grow best in slightly acidic, well drained soil which has a high organic content. A pH of 6.5 to 7.0 might be considered ideal. Daylilies require liberal amounts of  water and food  in order to perform well. Daylilies  shouldn't be planted to close to trees or shrubs which compete for the moisture and nutrients. . Although daylilies can tolerate drought, they perform best when they receive a deep watering of an inch of water or more each week. More frequent watering may be necessary if they are planted in sandy soils. A spring pre-bloom application of manure,  and/or compost, or a good complete fertilizer such as 5-10-10 or 5-10-5  with trace elements is very beneficial. A low nitrogen fertilizer (3-12-12) should be applied in the late summer or early fall. Removal of unintended seedpods which weakens the plant will increase the number of blooms for the following season.
 

Dividing and Planting Daylilies:
After Daylily clumps grow for several years, it becomes necessary to divide and separate the plants. If clumps are allowed to grow too large, plant performance will diminish. Over crowded clumps will have fewer blooms as time goes by.

Daylilies can be divided every three to four years. The best time to transplant or divide plants in the south is in early to mid Fall. Some prefer transplanting in early spring. I feel it is beneficial to transplant after bloom season, when the days grow cooler. This method also allows the plant to become established over the winter, and perform better the following year.  Dig the entire plant up and gently pull the leaf fans apart, with each division having a minimum of 3 fans.  In large clumps it may be necessary to cut the division with a sharp long blade butcher knife. A sharp shovel will work as well, but with less control. Newly divided plants may not flower the first year after division.
 

Preparing new Daylily beds:
Healthy soil is the most important goal for any garden, Most of my beds are 5 feet wide by 40 feet long (200 sq. ft.). When preparing new bed, I order a soil analysis from Texas A&M. I strive to keep my soil PH at 6.5 to 7.0 for my Daylilies and Perennials.

My new beds are amended as follows in 200 sq. ft. beds.

This soil amendment method is for mature plants. However, there is nothing in it that would damage seedling. However I also use my 9 month seedling formula to encourage early blooming in 9 months. Heavy feeding produces blooms on about 60% of my seedlings the first year. The heavy feeding stops when seedlings bloom the first time.

Planting Daylilies:
Prepare the planting area by digging a hole larger than the root ball, and  down at least a foot to loosen the soil. Mix in compost, well-rotted manure, sand, or peat moss thoroughly, and then form a mound in the center of the hole. Set the plant in place with the roots spread on all sides of the mound, at the depth at which it was originally growing. Never plant daylilies with the crown (where foliage and roots join)  more than 1 inch deep. Add the soil around the roots firming it as you go. When the hole is half full with soil, water it very well to insure good soil to root contact, and then add the remaining soil. Firm the soil again, leaving a slight depression around the plant to act as a reservoir and water thoroughly. A good mulch of Pine Needles, wood chips or bark will help to preserve the moisture in the summer, as well as helping to control the weeds.
 

Pests:
A number of  pests can damage Daylilies.  The most problematic for us is the thrip (during years with warm winters and dry springs).  These little insects are seldom seen,  but can cause bud damage during early scape formation.  Effected buds grow into flowers with color distortions, small bumps, and sometimes deformed petals and sepals.  Dark colored flowers, such as reds and purples, are often the most drastically damaged. Thrips seem to do little damage to the overall health of the plant.  A spray mixture of Avid or Orthene is very effective in combating thrips, if sprayed on plants in early spring before scapes appear. I would recommend contacting a local agriculture extension agent  for recommendations in your area.

Aphids and Spider Mites can cause significant foliage damage if diagnosed and treated. A solution of soapy water will help control these pests. However with heavy infestations and insecticide may be needed. I have used Orthene and Malathion to control these insects. Follow instruction provided by the manufacturer.
 

Daylily Rust:
Daylily rust is caused by the fungus Puccinia hemerocallidis and affects the leaves and scapes. It is not a new disease of daylilies, having been reported previously in China, Taiwan, Korea, Japan and Russia (Sakhalin, Kuriles and Siberia *). Unfortunately, the disease has now arrived in North America, and was first identified in the United States in August 2000.  Because of widespread shipping of infected plants, by late 2001 daylily rust had been identified in approximately 30 US States,  In nature  the main method of rust spread is by wind borne spores.

Daylily Rust is said to die with prolonged exposure to freezing temperatures. Unfortunately, here in the South we seldom see killing frost. A regular spraying program is required to keep rust under control in most southern states. There are several fungicides available for controlling rust. I use Headline and Bayleton 50 on a 10 day, rotation with a tablespoon of dish washing soap added. Spraying for rust requires discipline. The reoccurrence of rust is imminent  when spraying is stopped in the hot humid spring and summer. Additional information can be found on The Daylily Rust Information Page.