Landscape - Strategies to Reduce Winter Damage

I recently had a conversation with a colleague on reducing winter damage in boxwoods. This brought to mind the whole subject of reducing winter damage. Dr. Ann Gould and Dr. Gladis Zinati had a good article on the subject in a recent Rutgers newsletter and I have reprinted their recommendations with some of my own comments in italics.

Strategies to minimize wind exposure, winter injury, and sunscald include:

• Install physical barriers such as canvas, burlap, or wood slats on the exposed sides to reduce winter desiccation (the screens should be placed two feet away from the tree or shrub and anchored securely). Plant wraps can be used for cold sensitive plants that are important in the landscape.

• Select the appropriate plants (e.g. pine, spruce or juniper) as windbreaks in areas of high exposure to wind (northwest side).

• Apply sufficient moisture in the root zone before the soil freezes in the fall, and mulch the ground to retain moisture in the winter. (avoid excessive watering however)

• Avoid late summer and early fall fertilization (this simulates and encourages plant growth late in the season which may not harden off properly for the winter).

• Select ornamental plants that exhibit medium to high tolerance to low temperatures (use references that give cold hardiness information)

• Protect conifers and broadleaf evergreens from drying by spraying antidessicants in late fall and throughout the winter months when temperatures are above 45 F. You must have good coverage and apply when temperatures are not to low.

• Prevent winter sunscald in newly planted, thin barked trees (such as maple, tuliptree, ash and crabapple) by wrapping the trunk with burlap or other tree wrapping materials (the wrap can be kept in place up to two years).

• Prune dead twigs and branches that serve as sites for secondary pests.

• Fertilize with complete fertilizer, if soil test results showed nutrient deficiency, by spreading the fertilizer on the ground in early spring. Potassium is important in overwintering.

Information reprinted from "Winter Injury in theNew Jersey Landscape" by Ann B. Gould, Ph.D., Specialist in Plant Pathology and Gladis Zinati, Ph.D., Specialist in Nursery Management in the November 6, 2008 edition of the Plant and Pest Advisory, Landscape, Nursery, and Turf Edition from Rutgers University.