No wonder gardeners everywhere love growing daylilies - they're pest and disease resistant!

Daylily Pests

Some insects are attracted to daylilies, but they rarely do much damage. Here are some to look out for:

Spider mites: these are the most common daylily pests, and while they're not exactly welcome guests, they seldom do any real damage to the plants. Spider mites are generally most active in warm climates and in hot, dry weather, and the easiest way to keep their numbers down is to hose down the foliage regularly.

Slugs and snails: These nocturnal pests feed on tender new growth at night and hide in cool dark places (like under mulch or foliage) during the day. Avoid infestations by keeping the area tidy (no piles of dead leaves or foliage) and by hosing the plant down occasionally. If you do get a slug/snail infestation, treat with a commercial product specifically formulated to get rid of snails and slugs. Do NOT use kelthane on daylilies - it can harm the plant.

Aphids: There is a type of aphid that feeds only on daylilies, and an infestation can be difficult to eliminate. Aphids are most active in cool weather, so look for them in spring and fall in temperate climates and all winter long in warmer areas. Commercially available pesticides formulated specifically to combat aphids are the best defense.

Diseases

Disease in daylilies is seldom a problem for home gardeners. The better the daylily cultivar is suited to the climate, the less environmental stress it will experience and the more disease resistant it will be.

Crown and Root Rot: this devastating disease isn't common, but it can be triggered by a number of factors ranging from weather conditions to bacterial pathogens, poor soil aeration, and soil that is too wet. Signs of crown and root rot include yellowing of the foliage, a mushy feel to the plant tissue, and occasionally a foul smell.

Rot is very difficult to treat, so the best practice is to do everything possible to avoid it. Make sure your plants are in loose, well-aerated soil; don't over-water or over-fertilize; don't plant your daylilies too deep; and select varieties that are well-suited to your geographic location.