Winter Damage Seen on Meserve Holly and Rhododenrons

Despite a warm start, the winter of 2007 was particularly hard on the broadleaf evergreens on the grange. The rhododendrons and the female meserve holly have large swaths of dead, brown, and dessicated leaves.

To quote the experts,

"Winter burn is caused from desiccation, which is a type of dehydration injury. When roots are in dry or frozen soil, water lost through transpiration cannot be replenished by the roots and dehydration occurs. Water loss through transpiration is normally low during winter months, but it increases when plants are subjected to drying winds or are growing in warm sunny spots."

Source: High Plains Journal, "Winter Damage to Broadleaf Evergreens" available here.

Moreover, chlorophyll is destroyed at temps below 28 F, leading to further damage. Fear not, however, for winter, like ladybugs and pretty pink flowers, is a fact of nature.

According to the University of Minnesota,

"If an evergreen has suffered winter injury, wait until mid-spring before pruning out injured foliage. Brown foliage is most likely dead and will not green up, but the buds, which are more cold hardy than foliage, will often grow and fill in areas where brown foliage was removed. If the buds have not survived, prune dead branches back to living tissue. Fertilize injured plants in early spring and water them well throughout the season. Provide appropriate protection the following winter."

Source: University of Minnesota, Protecting Trees and Shrubs Against Winter Damage, available here.