Growing Green

By Robin Trott, Extension Educator

Winter burn poses a threat to various evergreen species, including boxwood, holly, fir, pine, arborvitae and juniper. It affects plants in open, unprotected areas exposed to harsh winter conditions, particularly those that are marginally hardy. The consequences can be severe, leading to plant death or extensive damage requiring replacement.

Identifying Winter Burn Symptoms

As snow melts and spring temperatures rise, winter burn symptoms become apparent. Foliage browning starts at branch tips and progresses inward. On broad-leaved evergreens, leaf edges brown first, followed by entire leaves. South, southwest or west facing foliage is most vulnerable. Affected foliage may drop in spring, continuing through mid-summer. In extreme cases, entire plants can perish.

Understanding the

causes of winter burn

Several factors contribute to winter burn. Plants with shallow or poorly developed root systems and recent transplants are more susceptible. Warm fall temperatures which delay plant dormancy, sudden winter temperature drops and exposure to deicing salt contribute. Winter winds and extended cold periods increase the risk, especially if below normal temperatures persist into April.

Saving plants affected by winter burn

For evergreens like arborvitae, boxwoods, junipers, and years, pruning dead or damaged tissue in mid-spring, after new foliage emerges, is crucial. Scratching the bark and checking for green tissue underneath helps determine viability. Pines, spruced, and firs often produce new growth that replaces damaged needles without pruning. If an entire evergreen is brown, recovery is unlikely, and replacement with a better suited plant is recommended.

Preventing winter burn

Strategic planning is essential to prevent winter burn. Plant cold-hardy species in protected areas, avoiding late – season pruning, ensuring proper mulching, adequate watering and protecting plants from winter winds and sun. Late summer or fall fertilization should be avoided, and soil testing can guide appropriate fertilization.

Conclusion

Understanding winter burn and implementing preventive measures is crucial for evergreen plant health. Choosing the right plants, providing proper care, and taking proactive steps can minimize the risk of winter burn, ensuring the longevity of cherished evergreens.

For Pope and Douglas County residents with questions, contact Robin Trott, Extension Educator, at 320-762-3890 or trot0053@umn.edu.

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“The pine stays green in winter… wisdom in hardship.” ~Norman Douglas