It’s no surprise that weather can take a toll on your landscaping. The lack of rain this summer and fall has stressed many plant species. Rhododendrons, azaleas, boxwoods, holly bushes, arborvitaes, roses, and hydrangeas are all at risk of unsightly damage and die-off from winter burn.

Winter Burn Explained

Winter burn, also known as desiccation, occurs when a plant’s leaves give off more water than can be absorbed by its roots. Desiccation is a natural and annual occurrence. But this fall, the soil is significantly drier than average. When the soil freezes, water struggles to reach a plant’s roots. The plant’s ability to absorb life-sustaining nutrients is significantly compromised, and leaves, needles, and stems continue to lose moisture. Additional environmental conditions, such as leaf scorch (from snow glare) and drying winds, may result in winter burn. 

Signs and Symptoms – How To Identify Affected Plants

Winter burn is when plants and shrubs exhibit symptoms of poor health following the dormant or winter season. Symptoms may include:

• Leaves and needles may turn brown or yellow and drop off through the spring and summer seasons.
• Bloom quality and quantity may be compromised, resulting in fewer, smaller flowers that display less vibrant color.
• Infestations of pests and diseases.
• Plant death.

Prevention and Protection – What You Can Do to Ensure Plant Health

• Apply regular applications of antidesiccant spray to minimize leaf transpiration and water loss.
• Apply mulch at the shrub base to conserve available moisture.
• Fertilize regularly and water deeply until the ground freezes to ensure plant health throughout the winter.
• Wrap plants that might sustain damage.
• Treat newly planted nursery stock for protection.

Antidesiccant Sprays – An Optimal Solution

Antidesiccants help minimize water loss by covering exposed leaf and needle surfaces with a waxy, attractive, shiny substance, which creates a protective barrier on the leaf, needle or stem. Consistent and uniform application is critical to protect a plant or shrub and ensure its health throughout the year.

• Late fall applications are optimal.
• Apply before the ground solidly freezes (typically when New Hampshire has five consecutive days of below-freezing temperatures).
• Apply before the first significant snowfall.
• Apply before the plant goes dormant for the winter.
• The timing of antidesiccant application is critical. It is never advisable to cover leaves and needles when a plant is still actively releasing water from its foliage (transpiring). Certified landscape professionals will know when and how to apply antidesiccants.
• Repeat applications will likely be necessary to ensure the plant stays covered throughout the entire winter.

Not every plant will benefit from antidesiccant treatment. For example, the treatment of blue spruce trees should be avoided.

Belknap Landscape’s Plant Health experts and certified applicators will ensure the best possible results for your landscape investment. New Hampshire has trusted us for almost 40 years to provide optimal solutions for complex plant health issues. Call or email us to schedule a visit; we’d be delighted to discuss your unique property care needs personally.