The daylily (Hemerocallis sp.) is a perennial flowering plant that derives its name from the fact that each bloom lasts just one day. There are a number of flower colors and shapes from which to choose, depending upon cultivar. Daylilies thrive in the warm climate of the Hawaiian islands and are used mainly as a border plant. Consider the 'Bitsy' variety, with yellow flowers, for your Hawaiian daylily garden.
Provide the daylily with the appropriate amount of sun. Daylilies generally require at least a half day of sun or a full day of filtered sunlight. Varieties with darker flowers require afternoon shade in order to maintain the intensity of the flower color. Keep in mind that due the relative humidity, Hawaiian sunshine can be deceiving; it may be a lot hotter than it feels on your skin.
Water the daylily according to the amount of rainfall received in your area in Hawaii. The plant requires 1 inch of water per week during the blooming period (which can be year-round for some varieties grown in the islands). A soaker hose can provide slow, deep irrigation for the daylily without getting the leaves wet. Moisture on the leaves promotes fungal diseases.
Fertilize the daylily once a year during Hawaii's cooler months, January or February, with a 13-13-13 formula at the rate suggested on the fertilizer label. Fertilize either late in the day or early in the morning to avoid burning the plant. Water prior to applying fertilizer.
Deadhead the daylily frequently. Removing spent flowers as they die helps to keep pests and disease at bay.
Inspect the daylily for signs of rust. This is a fungal disease that is becoming more common on daylilies in Hawaii. The symptoms include orange-colored powder on the leaves. Remove any infected leaves and destroy them. The fungus spores are easily transmitted by breezes so the mere act of moving infected leaves can spread the spores.