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Winter Burn on Evergreens

With unexpected snow and a prolonged winter comes unexpected winter burn on evergreens.

Winter winds can pull moisture from the foliage of evergreens. If the plant cannot draw water from the ground to replace what is lost, the result is a browning, or desiccation, of leaves or needles. This is called Winter Burn. As winter conditions vary from year to year, this damage may be more prevalent in some years versus others. Broadleaf evergreens (boxwood, holly, rhododendron, and euonymus) generally exhibit more damage because they have more exposed leaf area than needled evergreens.

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SYMPTOMS

Evergreen plants may look fine during the winter months, but as the temperatures begin to warm in spring, these same plants may begin to turn brown.  The browning may happen on stem tips, in larger patches, or throughout the plant.

The extent of the damage may depend on how much of the plant was exposed to the drying, cold winds.  It can be especially noticeable on the windward side of evergreens. If snowfall had covered a portion of the plant, only the exposed tips may exhibit damage.  If the plant was fully exposed, damage may be seen over the entire plant.

TREATMENT

  • Pruning:  Severity of damage should be assessed in spring.  Although leaves may be brown, there may be life left in the stems.  Evergreens begin to push out fresh, new growth in very late spring. If leaf buds begin to swell on the stems, the plant may fully recover from winter damage.  The discolored leaves will eventually drop and new growth will begin to fill in the empty patches. Once the plant has flushed with new growth, you can determine how much dieback actually occurred and how much pruning can be done.
  • Watering:  Once the soil begins to thaw, begin a regular watering schedule to help damaged evergreens recover.  An inch of water to the root zone per week is recommended. If soils are already wet from snow melt or spring rains, hold off on additional watering.  Too much water can cause root rot.
  • Fertilization:  A spring application of fertilizer, like Espoma Holly-Tone, can be helpful, but is not always necessary.

PREVENTATIVE MEASURES

  • Evergreens should be watered throughout the fall.  This gives plants access to moisture heading into winter months.
  • Broadleaf evergreens (rhododendron, holly, euonymus and boxwood) benefit from a late fall application of an anti-transpirant spray, such as WiltPruf. This can prevent moisture loss in the foliage.
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