Anti-desiccants beneficial to evergreens as long winter sets in
Winter winds here in Western Pennsylvania can be very drying, especially for evergreen trees and shrubs. If you grow azaleas, rhododendrons, hollies or any needled evergreens, consider applying an anti-desiccant to the plant before winter sets in. Though there are many brands of anti-desiccants in the nursery trade, Wilt-Pruf, Moisturin, and TransFilm are three popular brands.
Anti-desiccants leave a thin, waxy film over the tiny pores on the surface of the plant's leaves or needles, effectively sealing them off and keeping any moisture inside of them from evaporating away as water vapor. Most, but not all, anti-desiccants are made of pine resin.
Broadleaved evergreens are particularly prone to winter desiccation; that's why the leaves of rhododendrons and laurels curl up and fold over on themselves. They're trying to protect those tiny pores on their lower leaf surfaces to stave off moisture loss. If we don't get any precipitation for a long period of time over the winter, drying winds have an even greater impact on plant health. If the ground is frozen and the plants don't get any water, winter dieback can occur.
Anti-desiccants help prevent winter scorch, dieback, and foliage browning on most evergreen plants. It's particularly valuable on plants that were planted within the last season.
To apply an anti-desiccant, spray on both upper and lower leaf surfaces and follow label instructions. Only apply when temperatures are between 40 and 50 degrees F and a freeze or rain is not expected within 24 hours.
Because it's best to apply anti-desiccants after evergreens have shifted into dormancy, December is the perfect time to complete this chore. Read the label carefully because some evergreens do not respond well to the application of anti-desiccants and may drop their leaves. Only spray anti-desiccants on the plants listed on the label.
As winter progresses, a second application may be necessary in February or March, if we get a few warm days. Even with anti-desiccants on the foliage, be sure to keep your evergreen trees and shrubs well-watered through the winter months, especially if they're newly planted.
If you have just one or two trees or shrubs you'd like to protect and you don't want to apply anti-desiccants, consider erecting a peripheral barrier of burlap to protect these plants from drying winds. Surround the entire plant with a ring of 1-x1-inch hardwood stakes hammered into the ground about a foot away from the plant. Use a staple gun to attach a single layer of burlap to the outside of the stakes and surround the plant. Do not put any burlap on the top as it cuts off air circulation and can collect heavy snow.
Anti-desiccants are also useful for keeping cut holiday greens and live Christmas trees from drying out too quickly. Dunk wreathes, garlands, and evergreen boughs in a tub of water with the anti-desiccant added. Or, spray the greens with the product until they're soaked, then shake off the excess moisture, allow them to dry, and use them indoors or out. Christmas trees can be sprayed with the anti-desiccant before putting them up indoors.
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: A Natural Approach to Pest Control” and “Good Bug, Bad Bug.” Her website is jessicawalliser.com.
Send your gardening or landscaping questions to tribliving@tribweb.com or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.
