Anti-desiccants stave off winter water loss in rhododendrons, mountain laurels
Q: I wondered what you think of Wilt-Pruf and other products, specifically for use on rhododendrons and mountain laurels in the winter.
A: Anti-desiccants, like Wilt-Pruf and other brands, are meant to stave off water loss through the winter months and during times of stress. They work by “sealing” the tiny pores on a leaf's surface and thereby preventing water vapor from exiting through them.
Because their leaves are large and they remain intact through the colder months, the winter is particularly difficult on broad-leaved evergreens such as rhododendrons, mountain laurels, boxwoods, azaleas and hollies. The bigger leaves on these plants have many leaf pores, which makes them more prone to drying out in winter winds. This is especially true if we do not get any precipitation for long periods of time or if the ground remains frozen and water is unavailable to them.
Spraying broad-leafed evergreens like these with an anti-desiccant product will indeed help prevent the symptoms of dehydration, including leaf browning, winter die-back and curled leaves. Anti-desiccants are best applied to upper and lower leaf surfaces on a day where temperatures are above freezing and rain is not predicted for twenty-four hours. Read the label well before use, as these products cannot be used on certain plants without causing issues with leaf discoloration and leaf drop. Apply only to the plants specified on the label.
Because anti-desiccants break down as the winter progresses, a second mid- or late-winter application is a good idea. Choose a day that is well above freezing and when the weather is predicted to stay above freezing for a day or two.
If you don't want to go the anti-desiccant route, but are interested in protecting your broad-leafed evergreens from winter dehydration, be sure to keep all your trees and shrubs well watered through the winter months. This is especially true for newly planted or transplanted specimens. Add any necessary supplemental irrigation on warmer days when the top few inches of soil are less likely to be frozen and the water can soak in.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio. She is the author of several gardening books, including “Grow Organic” and “Good Bug, Bad Bug.” Her website is www.jessicawalliser.com.
Send your gardening or landscaping questions to firstname.lastname@example.org or The Good Earth, 503 Martindale St., 3rd Floor, D.L. Clark Building, Pittsburgh, PA 15212.
Show commenting policy
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.