Bringing Boxwood Back to Life: A Guide to Post-Winter Care

Reviving Boxwood Hedges After Winter’s Wear

Winter can be a harsh season, and its effects often linger in the garden long after the snow melts. If you’re facing a less-than-vibrant boxwood hedge this spring, you’re not alone. These elegant evergreens, prized for their formal structure and lush appearance, can sometimes look a little worse for wear after enduring the cold. The good news is that with some careful attention and the right strategies, you can nurse your boxwoods back to their former glory.

Assessing the Damage

Before diving into solutions, take a good look at your boxwood. Identify the specific issues you’re dealing with. Common winter-related problems include:

• Winter Burn: This appears as bronzing or browning of the foliage, particularly on the outer edges of the plant. It’s caused by the combination of cold temperatures, drying winds, and sunlight, which can lead to dehydration.
• Desiccation: Similar to winter burn, desiccation occurs when the plant loses moisture through its leaves faster than it can absorb it from the frozen ground.
• Frost Damage: Severe frost can damage the plant’s cells, leading to leaf discoloration, dieback, and even stem damage.
• Snow Load: Heavy snow can weigh down branches, causing them to bend, break, or splay awkwardly.

Carefully examine the extent of the damage. Is it localized or widespread? Are the stems and branches still flexible and alive, or are they brittle and dry? This assessment will guide your treatment plan.

The Recovery Plan

Here’s a step-by-step guide to helping your boxwood hedges thrive again:

1. Pruning and Shaping

• Timing: The best time to prune boxwood is in late spring or early summer, after the danger of severe frost has passed and when new growth is actively emerging. Avoid pruning in late summer or fall, as this can stimulate new growth that may not harden off before winter.
• Technique: Use sharp, clean pruning shears or hedge trimmers. Remove any dead, damaged, or diseased branches. Make clean cuts just above a healthy bud or branch. If the damage is localized, you can selectively prune the affected areas. For more severe damage, you may need to cut back the hedge more extensively. Don’t be afraid to prune back hard if necessary; boxwoods are generally resilient and will regrow.
• Shaping: Now is also the time to restore the desired shape of your hedge. Lightly trim the sides and top to encourage dense, compact growth. Avoid removing too much foliage at once, as this can stress the plant. Remember that boxwood responds well to regular pruning, so maintaining the shape will be an ongoing process.

2. Watering and Fertilizing

• Watering: Boxwood prefers well-drained soil but needs consistent moisture, especially during dry spells. Water deeply and regularly, particularly during the first year after planting or after severe pruning. Avoid overhead watering, which can promote fungal diseases; instead, water at the base of the plant.
• Fertilizing: Boxwood benefits from regular fertilization. In early spring, apply a balanced, slow-release fertilizer formulated for evergreens. Follow the manufacturer’s instructions for application rates. Avoid over-fertilizing, as this can burn the roots and lead to excessive growth, making the plant more susceptible to pests and diseases. Consider a soil test to determine specific nutrient needs.

3. Mulching

• Benefits: Applying a layer of mulch around the base of your boxwood hedges offers several advantages. Mulch helps to retain soil moisture, suppress weeds, and regulate soil temperature, protecting the roots from extreme heat and cold. It also slowly decomposes, adding organic matter to the soil.
• Materials: Use organic mulches such as shredded bark, wood chips, or compost. Avoid using mulches that are too fine, as they can compact and suffocate the roots. Spread the mulch in a layer 2-3 inches deep, keeping it a few inches away from the stems to prevent rot.

4. Pest and Disease Management

• Boxwood Caterpillars: The box tree moth (Cydalima perspectalis) has become a significant threat to boxwood in some regions. Caterpillars feed on the foliage, causing defoliation and weakening the plants. Look for signs of infestation, such as webbing, frass (caterpillar droppings), and partially eaten leaves. Hand-picking caterpillars, introducing natural predators, or using insecticidal soap or Bacillus thuringiensis (Bt) can control infestations.
• Boxwood Blight: This fungal disease (Calonectria pseudonaviculata) is another major concern for boxwood growers. Symptoms include leaf spots, defoliation, and stem cankers. Remove and destroy any infected plants. Improve air circulation by pruning the hedge to promote dryness. Fungicides may be used preventatively or to treat early infections, but they are often not effective once the disease has become severe.
• Other Pests and Diseases: Monitor your boxwood for other potential problems, such as spider mites, scale insects, leaf miners, and fungal diseases like Volutella blight. Early detection and prompt treatment are crucial for preventing serious damage. Consult with a local gardening expert or extension office for advice on pest and disease management in your area.

5. Protection from the Elements

• Wind Protection: Boxwood is susceptible to winter burn and desiccation, especially in exposed locations. Consider planting windbreaks, such as other evergreen shrubs or fences, to shield your hedges from harsh winter winds. You can also use burlap or other protective materials to wrap the plants during the coldest months.
• Sun Protection: In areas with intense winter sun, boxwood can suffer from winter burn. Provide some shade during the winter months by using shade cloth or strategically positioning the plants. You can also consider planting boxwood in a location that receives some shade during the winter months.
• Snow Load Management: If you live in an area with heavy snowfall, be vigilant about removing snow from your boxwood hedges. Use a soft broom or your hands to gently brush off the snow, preventing branches from breaking under the weight. Avoid using salt or other de-icing agents, which can damage the plants.

Long-Term Care

Maintaining healthy boxwood hedges requires ongoing care and attention. Here are some additional tips for long-term success:

• Regular Inspection: Inspect your boxwood hedges regularly for signs of pests, diseases, or other problems. Early detection allows for prompt treatment and prevents small issues from escalating into major problems.
• Proper Spacing: When planting new boxwood, space the plants appropriately to allow for good air circulation. This helps to reduce the risk of fungal diseases.
• Soil Improvement: Boxwood thrives in well-drained, slightly acidic soil. Amend the soil with organic matter, such as compost or well-rotted manure, to improve drainage and fertility.
• Variety Selection: If you are planting new boxwood, consider choosing varieties that are known to be more cold-hardy or disease-resistant.
• Professional Advice: Don’t hesitate to consult with a local gardening expert or arborist for personalized advice on caring for your boxwood hedges.

Conclusion

Reviving a winter-worn boxwood hedge takes time, patience, and the right approach. By following these steps, you can help your plants recover, thrive, and regain their elegant beauty. Remember that consistent care, including proper pruning, watering, fertilizing, pest and disease management, and protection from the elements, is essential for keeping your boxwood hedges healthy and vibrant for years to come. With a little effort, you can enjoy the timeless charm of these classic garden plants season after season.