Daylily

Hemerocallis

DAYLILY RUST ALERT

For the past two years, a new foliar disease of daylilies -- called daylily rust -- has slowly been working its way throughout the United States. According to the Florida Department of Agriculture and Consumer Services, the consensus is that P. hemerocallidis is the proper name for the rust pathogen. The ‘P’ stands for Puccinia.

A USDA sponsored New Pest Advisory Group (NPAG) believes that the disease will be a serious pest of daylilies because it has a short incubation period and rapid spread. Until this daylily rust surfaced, there were basically no diseases of daylilies in the United States.

Different varieties of daylily have different susceptibilities to the rust. The spores can be spread by wind or by human movement of plants. Although not all daylily cultivars have been tested for susceptibility, preliminary daylily cultivar evaluations by the University of Georgia indicate the following ratings:

• Highly susceptible varieties: Pardon Me, Lemon Yellow, Pandora's Box, Little Gypsy Vagabond, Karie Ann, Colonel Scarborough, Quannah, Ming Toy, Double Buttercup, Russian Rhapsody, Irish Ice, Imperial Guard.

• Moderately susceptible varieties: Happy Returns, Prelude to Love, Gertrude Condon, Stella D'Oro, Joan Senior, Butterflake, Wilson's Yellow, Star Struck, Crystal Tide.

• Least susceptible varieties: Mac the Knife, Yangtze, Holy Spirit and Butterscotch Ruffles.

And, finally, the Alabama Cooperative Extension System suggests the following: Remove the rust-spotted leaves. Daylily rust is bright orange and when you rub it, you can smudge it. Other markings on the leaves may simply be from aphids or just regular wear and tear. To make sure, you should take a couple leaves to your local extension office. Handle them with care. Place suspect leaves between paper towels and put them in ziploc plastic bags. This spore is easily spread and you want to make sure you're not compounding the problem.

Homeowners can use Spectracide Immunox (myclobutanil) and ferti-loam Systemic Fungicide (propiconazole) to thwart this very serious pest. You will need both fungicides and you should use them alternately. Refer to the product labels for application rates and instructions.

I've kept a close watch on my daylilies and did find some daylily rust. A couple months ago I cut back the affected plants to the ground. They responded with bushy new growth, more blooms and clean plants!! I keep checking the new growth, but no daylily rust. This seems to be a more efficient way of controlling the disease than spraying. I did find a web site with some excellent pictures of what daylily rust looks like and, more importantly, what it doesn't look like. You can read about it here.

Daylilies are eye-openers in either a border or a cutting bed, especially when grown in clumps of 10 plants or more of the same color. They form huge clumps quickly and should be divided every couple years. A crowded lily will not produce big flowers.

Daylilies are one of the most popular perennials grown in Florida. Until daylily rust reared its ugly head, they were relatively free from serious pests. On occasion aphids, thrips or spider mites can find your daylilies. However, if you monitor your gardens once or twice a week you'll find them before they do much damage. (Monitoring simple means walking through your gardens so you are familiar with what the plant looks like and how it is performing. Use a 10x magnifying glass to spot these tiny pests and always check the undersides of leaves.)

They adapt well to landscape plantings. Daylilies can be used as foundation plantings and make an excellent contrast to evergreen shrubbery. When picking the color for a foundation planting, keep in mind the color of your home. Yellow looks best against redwood, brick or dark backgrounds. The darker flower colors can be used against white or light backgrounds.

Daylilies are tough thrive almost everywhere in Florida: the mucky Everglades, rocky Dade County, central Florida sands and the northern clay hills. Darker colored reds and purples grow best in partial shade. Lighter yellows, pinks and pastels need full sun to bring out their gentle colors. Amend the soil generously with organic matter. And, don't forget to mulch them as they like their little feet cool. It helps to plant color-coordinated annuals around the lilies because they will help keep the soil cool. Fertilize in the fall, spring and mid-summer. I use Sunnyland 2-10-10 that I buy in 20 lb. sacks.

Daylily is also an excellent ground cover because its arching, spreading habit will quickly fill in. Daylilies should be watered deeply once a week during their blooming time. Soak the soil 8 to 12 inches deep. Don't do any overhead watering in the heat of the day because that will hurt the open blooms. Established plants will tolerate temporary droughts, but a prolonged drought will cause problems. Once established, daylilies need virtually no care. In fact, they thrive with minimal attention. A fall cleanup to remove withered, dried foliage from the bed helps keep plants disease-free. Daylilies make excellent cutting flowers. Cut the flower stems in the early morning, add a teaspoon of sugar per quart of water in the container they will be displayed in. All the buds on the stem will open, providing blooms several days in a row.

Do follow one rule when growing lilies -- whenever possible, always let the leaves on the stalk turn yellow and fall off because it's the leaves that feed the warehouse underground.