Protecting Broad-leaved Evergreens for Winter: Anti-Desiccant Spray

The temperatures are dropping rapidly here in the northeast and it is time to apply anti-desiccant spray to your broad-leaved evergreens to protect them from winter damage.

What is desiccation?:   Certain broad-leaved evergreens are susceptible to winter burn and drying from harsh winter winds here on Long Island and anywhere where winter temperatures drop below freezing. Desiccation, or extreme drying is caused by moisture loss from the leaves by transpiration. A precautionary measure for this drying is the use of an anti-desiccant, which can help to prevent damage to your landscape plants.  Anti-desiccant spray is an organic based spray application that lasts for approximately three months throughout the winter, and helps to prevent water loss from your evergreens.

Which plants should be sprayed with an anti-desiccant?: Apply an anti-desiccant spray to your broad-leaved evergreens such as holly, rhododendron, cherry laurel, skip laurel, mountain laurel, Japanese skimmia, leucothoe, aucuba and boxwood when the daytime temperatures start falling below 50 degrees (around Thanksgiving here in zone 7 Long Island). Apply when the temperatures are above freezing and there is no threat of rain or frost within 24 hours. (This tip applies to areas going into their winter season-temperatures dropping below freezing: 0 degrees Celsius or 32 degrees Fahrenheit.)

When to Apply: Apply anti-desiccant when the daytime temperatures start falling below 50 degrees (late fall/early winter). Apply when the temperatures are above freezing and there is no threat of rain or frost within 24 hours.

Dangers: Be sure to read all directions on the label since anti-desiccants can cause photo toxicity on some narrow needled evergreens such as Arborvitae and Spruce that could cause more harm than winter burn.  Spraying in freezing temperatures will do harm to the plant.  Do not spray in freezing temperatures and allow time to dry before temperatures drop below 32^oF or 0^oC.

How often should I apply anti-desiccant?:  Sudden warm spells can trigger your evergreens to open their pores allowing for more water loss. If there is a winter thaw part way through the season it is recommended to re-spray your plants but only if the temperatures are to remain above freezing for at least 24 hours.

Where do I purchase anti-desiccant?:  The most commonly used brands of anti-desiccant are Wilt-Pruf, Vapor Guard and Transfilm that can be found in nurseries and garden centers. There is a new brand of anti-desiccant on the market which requires only one application. Ask your landscape professional for more information.

Informational Links:
A Guide to Northeastern Gardening on Facebook
Landscape Design by Lee on Facebook
NEGardening on Twitter

My Published Book: A Guide to Northeastern Gardening: Journeys of a Garden Designer on Amazon

Author:  Lee@Landscape Design By Lee 2016. All Rights Reserved.