Chapstick for Trees
Evergreen trees do not go into dormancy like hardwood trees because they retain their needles in the winter. When the ground freezes, these trees tap into the water stored in their leaves and stems. Sometimes trees exposed to hot sun or wind cannot keep up with the water loss from transpiration, dry out and desiccate. If these trees do not get moisture, they will turn brown and eventually die. Applying anti-desiccants on evergreen trees slows water loss from needles and helps trees withstand Denver’s dry winters.
What Is Desiccation?
As a part of their normal respiratory function, plants release water vapor into the air, which is usually not a problem since this moisture is replaced by its root system. Desiccation occurs when the tree cannot recover its transpiration water losses and starts to dry out. There are two causes for desiccation – the root system shuts down when the ground freezes or when dry wind or hot sun exposure removes more moisture from the plant than it can replace.
Treating Desiccation Damage
Once damaged by desiccation, there is no way to resuscitate the dead brown tissues, so prevention is the best tact. Newly planted trees need extra care so put them on a watering schedule. Mature evergreen trees and shrubs need much more water. Properly hydrated trees and shrubs can hold out longer against desiccating external forces. Mulch goes a long way in keeping moisture in the soil and regulating ground temperature. Please note that young evergreens need extra care for about five years after planting. If a tree dies, it is time for tree removal.
Broadleaf evergreens such as Boxwood, Aucuba, Holly, Rhododendron, and Laurels do not drop their leaves, so they are vulnerable to winter desiccation and death. Evergreen trees and shrubs planted on a windy spot or exposed to Denver’s hot western sun are also vulnerable to drying out. Anti-desiccants sprayed on evergreen foliage form a soft, transparent, flexible film that protects leaves and needles from drying out during the winter. The film protects plants from drought, high winds, sunscald, winter kill, and salt damage.
Gardeners use anti-desiccants to protect newly transplanted shrubs from drying winds and sunshine as they get established. Spraying protects bulbs going into storage. Some people spray anti-desiccants onto live Christmas trees and Halloween pumpkins to slow the drying process, making them last longer during the holidays. For more information about evergreen care, check out our Evergreen Tree Care Handbook.
There are a lot of do’s and don’ts when applying anti-desiccant. For example, Blue Spruces have waxy needles and do not benefit from anti-desiccant applications. Also, application timing is critical to not trap too much moisture in needles. Ross Tree has the expertise and equipment to apply anti-desiccants professionally to obtain the best results. Call 303-871-9121 or fill out a service request form.