Why’s the daylily looking so brown? | TribLIVE.com
Jessica Walliser, Columnist

Why’s the daylily looking so brown?

Jessica Walliser
Reader submitted photo shows what is likely to be common leaf scorch on daylily leaves.

Question: This is a photo of our daylily. The flowers are beautiful, but the leaves are striped with brown. Do you know what’s wrong with it and what we can do to keep it from happening in the future?

Answer: Daylilies (Hemerocallis species) are popular perennials for sunny areas of the landscape. Their flowers come in a broad range of colors, and the plants are fast growing and require very little care.

However, there are several common issues daylily growers face that can affect the health and appearance of the plants.

First, the most devastating daylily problem is probably daylily rust. This fungal disease didn’t arrive on North American shores until the early 2000s, but it has since spread to many different states, most likely via plants shipped from one region to another.

Caused by a fungal pathogen known as Puccinia hemerocallidis, daylily rust affects many different daylily cultivars. It’s not as problematic in northern states as it is in the south, since it doesn’t survive cold winters, but I’ve heard from some folks who have plants with symptoms.

The leaves are streaked with yellow and brown and you’ll see raised pustules on the leaf surface, particularly on the underside. When you rub the pustules, your fingertips will be orange from the spores. This pathogen will not kill plants, but it does make them look unattractive. Biofungicides based on Bacillus subtilis help prevent this pathogen, but it’s better to seek out resistant varieties.

I do not, however, believe that this is what’s going on with your plant.

Leaf streak

Another similar pathogen is daylily leaf streak. This disease is caused by a different fungus, and causes yellow, elongated splotches on the leaves, typically around the central vein. The pathogen occurs first at the leaf tip and then progresses down the leaf. There will be small brown flecks, but unlike daylily rust, there are no pustules or rust-colored spores.

It develops quickly in warm, wet weather. The spores are spread by humans and animals, and when they are splashed up onto the plant from the soil. Again, this pathogen will not kill your plant, but to prevent it, make sure plants are well spaced and use a biofungicide as a preventative.

Though this may be what’s causing the brown leaves on your plant, I suspect it’s more likely to be the following issue.

Leaf scorch

Leaf scorch is a very common physiological disorder of daylilies. It is not caused by a fungus or bacteria or virus. Instead, it’s caused by growing conditions.

Leaf scorch is evidenced by brown leaf tips and splotches on the leaves, and is especially evident in hot, dry weather. Though we had a wet spring, the last few weeks have been very hot and dry, which can cause leaf scorch to occur fairly quickly. It is largely an aesthetic issue and will not harm the plant.

I suggest “combing” through the plant with your fingers and pulling out any damaged leaves. Do this several times throughout the summer and the plants will continue to generate new leaves from the base, keeping the plant lush and healthy looking.

In fact, in my own garden, I groom my daylily plants as soon as their first flush of blooms fade. I do this by completely cutting the plant back down to the ground, including all the leaves and the dead flowering stems.

This causes a flush of new growth that is pristine and, with some daylily varieties, it will stimulate another flush of blooms.

Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden,” “Good Bug, Bad Bug,” and her newest title, “Container Gardening Complete.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to [email protected] or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.

TribLIVE commenting policy

You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.

We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.

While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.

We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers

We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.

We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.

We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.

We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.