How to Trim Overgrown Boxwoods: A Comprehensive Guide
Boxwoods are a classic and versatile shrub, prized for their dense foliage, formal appearance, and suitability for hedges, topiaries, and foundation plantings. However, even the most meticulously maintained boxwoods can become overgrown over time. Neglecting regular pruning can lead to a host of problems, including a misshapen appearance, reduced air circulation (increasing the risk of disease), and diminished vigor. Reviving an overgrown boxwood might seem daunting, but with the right tools, techniques, and a bit of patience, you can restore your boxwoods to their former glory and enjoy their beauty for years to come.
This comprehensive guide will walk you through the process of trimming overgrown boxwoods, covering everything from assessing the situation to performing the actual pruning and maintaining the shrubs afterward. We’ll break down the process into easy-to-follow steps, providing clear instructions and helpful tips along the way.
## Understanding Boxwood Growth and Pruning Principles
Before diving into the practical steps, it’s crucial to understand how boxwoods grow and the basic principles of pruning. This knowledge will help you make informed decisions and achieve the best results.
* **Boxwood Growth Habit:** Boxwoods are slow-growing, evergreen shrubs. Their dense foliage is composed of small, opposite leaves. They typically grow outward from the center, forming a rounded or pyramidal shape. Understanding their natural growth habit is crucial for shaping them effectively during pruning.
* **Pruning Goals:** Pruning serves several purposes, including maintaining shape, removing dead or diseased branches, improving air circulation, and stimulating new growth. In the case of overgrown boxwoods, the primary goal is often to reduce size and restore a more desirable shape while maintaining the plant’s health and vigor.
* **Timing is Key:** The best time to prune boxwoods is typically in late winter or early spring, before new growth emerges. This allows the shrubs to recover and put on fresh growth during the growing season. Avoid pruning in late summer or fall, as new growth may not harden off sufficiently before winter, making it susceptible to damage from frost.
* **Pruning Tools:** Using the right tools is essential for making clean cuts and avoiding damage to the boxwoods. The following tools are recommended:
* **Hand Pruners:** For small branches and stems (up to ½ inch in diameter). Bypass pruners, which make a clean, scissor-like cut, are preferred over anvil pruners, which can crush stems.
* **Loppers:** For larger branches (up to 1 ½ inches in diameter). Loppers provide more leverage than hand pruners, making it easier to cut thicker branches.
* **Hedge Trimmers:** For shaping and trimming the outer foliage of hedges or topiaries. Use hedge trimmers sparingly on overgrown boxwoods, as they can create a sheared appearance that looks unnatural.
* **Pruning Saw:** For branches larger than 1 ½ inches in diameter. A pruning saw has a narrow blade that allows you to make cuts in tight spaces.
* **Gloves:** To protect your hands from thorns and sap.
* **Eye Protection:** Safety glasses or goggles to protect your eyes from flying debris.
* **Sanitizing Tools:** Before and after pruning, disinfect your tools with a solution of 1 part bleach to 9 parts water or rubbing alcohol. This will help prevent the spread of diseases.
## Assessing the Overgrown Boxwood
Before you start pruning, take some time to assess the overall condition of the overgrown boxwood. This will help you develop a pruning plan and avoid making mistakes that could harm the shrub.
1. **Evaluate the Size and Shape:** Determine how much you need to reduce the size of the boxwood and what shape you want to achieve. Consider the surrounding landscape and the overall aesthetic you’re aiming for.
2. **Identify Dead, Diseased, or Damaged Branches:** Remove any dead, diseased, or damaged branches first. These branches are not contributing to the health or appearance of the shrub and should be removed to improve air circulation and prevent the spread of disease.
3. **Look for Crossing or Rubbing Branches:** Crossing or rubbing branches can create wounds that are susceptible to disease. Remove one of the branches to eliminate the friction and promote healthy growth.
4. **Assess the Density of the Foliage:** Overgrown boxwoods often have dense foliage that restricts air circulation and sunlight penetration. This can lead to weak growth and increased susceptibility to disease. Thinning out the foliage will improve air circulation and allow more light to reach the interior of the shrub.
5. **Consider the Age of the Boxwood:** Older boxwoods may be more sensitive to pruning than younger ones. Avoid removing too much growth at once from older shrubs, as this can stress them.
## Step-by-Step Guide to Trimming Overgrown Boxwoods
Now that you have assessed the boxwood and gathered your tools, you can begin the pruning process. Follow these steps for best results:
**Step 1: Remove Dead, Diseased, and Damaged Branches**
Using hand pruners, loppers, or a pruning saw (depending on the size of the branch), remove any dead, diseased, or damaged branches. Make clean cuts at the base of the branch or back to a healthy bud.
* **Dead Branches:** These branches will be brittle, dry, and brown or gray in color. They may also lack leaves or have discolored leaves.
* **Diseased Branches:** Look for signs of disease, such as discolored leaves, spots, or fungal growth. Remove diseased branches promptly to prevent the spread of the disease.
* **Damaged Branches:** These branches may be broken, cracked, or otherwise injured. Remove damaged branches to prevent further injury and promote healing.
**Step 2: Remove Crossing or Rubbing Branches**
Identify any crossing or rubbing branches and remove one of them. Choose the branch that is less desirable or that is growing in an undesirable direction. Make a clean cut at the base of the branch.
**Step 3: Thin Out the Foliage**
Thinning out the foliage is crucial for improving air circulation and sunlight penetration. Use hand pruners to selectively remove branches from the interior of the boxwood. Aim to remove about 10-20% of the foliage.
* **Focus on removing branches that are growing inward or that are blocking light from reaching the interior of the shrub.**
* **Make cuts at the base of the branch or back to a healthy bud.**
* **Avoid creating large gaps in the foliage. The goal is to thin out the foliage evenly, not to create a patchy appearance.**
**Step 4: Reduce the Height and Width**
Once you have removed the dead, diseased, and crossing branches and thinned out the foliage, you can begin to reduce the height and width of the boxwood. This is where you will start to reshape the shrub to your desired size and form.
* **Start by making cuts on the outer edges of the boxwood.**
* **Use hand pruners or loppers to cut back branches to a point where they will blend in with the overall shape of the shrub.**
* **Avoid making straight, shearing cuts, as this can create an unnatural appearance.**
* **Instead, make angled cuts that follow the natural contours of the boxwood.**
* **Step back frequently to assess your progress and make adjustments as needed.**
**Step 5: Shape the Boxwood**
After reducing the height and width, you can fine-tune the shape of the boxwood. This is where you will create the final form that you desire.
* **Use hand pruners to make small, precise cuts that refine the shape of the boxwood.**
* **Pay attention to the overall balance and symmetry of the shrub.**
* **Avoid creating sharp angles or abrupt changes in shape.**
* **Step back frequently to assess your progress and make adjustments as needed.**
**Step 6: Clean Up Debris**
Once you have finished pruning, clean up all the debris from around the boxwood. This will help prevent the spread of disease and improve the overall appearance of your landscape.
* **Rake up any fallen leaves, branches, or other debris.**
* **Dispose of the debris properly. You can compost it, burn it, or bag it for disposal.**
## Specific Pruning Techniques for Different Boxwood Styles
The general steps outlined above apply to most overgrown boxwoods, but there are some specific techniques that you can use depending on the style of boxwood you have.
* **Hedges:** When pruning boxwood hedges, the goal is to maintain a uniform height and width. Use hedge trimmers to shear the sides and top of the hedge, keeping the bottom slightly wider than the top to allow sunlight to reach the lower branches. Avoid cutting back into old wood, as this can result in bare patches. If the hedge is severely overgrown, you may need to prune it back gradually over several years.
* **Topiaries:** Topiaries are boxwoods that have been shaped into specific forms, such as balls, cones, or spirals. When pruning topiaries, the goal is to maintain the desired shape. Use hand pruners to make precise cuts that follow the contours of the form. Remove any stray branches that detract from the overall shape.
* **Natural Forms:** Some boxwoods are allowed to grow in their natural, unshaped form. When pruning these boxwoods, the goal is to maintain their health and vigor while preserving their natural appearance. Focus on removing dead, diseased, or damaged branches and thinning out the foliage to improve air circulation. Avoid making drastic cuts that alter the overall shape of the shrub.
## Dealing with Severely Overgrown Boxwoods: Renovation Pruning
If your boxwood is severely overgrown and has not been pruned for many years, you may need to resort to renovation pruning. This is a more drastic approach that involves cutting back the shrub to a much smaller size.
* **Renovation pruning should only be done as a last resort, as it can stress the boxwood and may even kill it.**
* **The best time to perform renovation pruning is in late winter or early spring, before new growth emerges.**
* **Start by removing all dead, diseased, and damaged branches.**
* **Then, cut back the remaining branches to about one-third of their original length.**
* **Make cuts at a 45-degree angle, just above a bud or a branch junction.**
* **After renovation pruning, the boxwood will look very bare. However, it should begin to produce new growth in the spring.**
* **Fertilize the boxwood in the spring with a balanced fertilizer to encourage new growth.**
* **Water the boxwood regularly during the growing season.**
* **In the following years, prune the boxwood regularly to maintain its shape and size.**
## Post-Pruning Care and Maintenance
After pruning your overgrown boxwoods, it’s important to provide them with proper care and maintenance to ensure their continued health and vigor.
* **Watering:** Water the boxwoods deeply and regularly, especially during dry periods. Boxwoods prefer well-drained soil and are susceptible to root rot if the soil is constantly soggy.
* **Fertilizing:** Fertilize the boxwoods in the spring with a balanced fertilizer. Follow the instructions on the fertilizer label. Avoid over-fertilizing, as this can lead to excessive growth and make the boxwoods more susceptible to pests and diseases.
* **Mulching:** Apply a layer of mulch around the base of the boxwoods to help retain moisture, suppress weeds, and regulate soil temperature. Use organic mulch, such as wood chips or shredded bark. Avoid piling mulch directly against the trunk of the boxwoods, as this can promote rot.
* **Pest and Disease Control:** Monitor the boxwoods regularly for signs of pests and diseases. Common boxwood pests include boxwood leafminers, boxwood mites, and boxwood psyllids. Common boxwood diseases include boxwood blight and Volutella blight. If you detect any pests or diseases, take action promptly to control them.
* **Regular Pruning:** After you have revived your overgrown boxwoods, it’s important to prune them regularly to maintain their shape and size. Prune boxwoods at least once a year, preferably in late winter or early spring. Regular pruning will help prevent the boxwoods from becoming overgrown again and will keep them looking their best.
## Troubleshooting Common Boxwood Pruning Problems
Even with the best intentions, you may encounter some problems when pruning overgrown boxwoods. Here are some common problems and how to troubleshoot them:
* **Bare Patches:** If you cut back too far into old wood, you may create bare patches in the foliage. To correct this, encourage new growth by fertilizing the boxwood and watering it regularly. You can also try lightly pruning the surrounding foliage to encourage it to fill in the bare patches.
* **Unnatural Shape:** If you make straight, shearing cuts, you may create an unnatural shape. To correct this, use hand pruners to make small, precise cuts that soften the edges and create a more natural appearance.
* **Stressed Boxwood:** If you remove too much growth at once, you may stress the boxwood. This can lead to yellowing leaves, stunted growth, and increased susceptibility to pests and diseases. To help the boxwood recover, water it regularly, fertilize it lightly, and protect it from extreme temperatures.
* **Disease Spread:** If you use unsterilized pruning tools, you may spread diseases from one boxwood to another. To prevent this, sterilize your pruning tools before and after each use.
## Safety Precautions
Before you start pruning, it’s important to take some safety precautions to protect yourself from injury.
* **Wear gloves:** Gloves will protect your hands from thorns, sap, and other irritants.
* **Wear eye protection:** Safety glasses or goggles will protect your eyes from flying debris.
* **Use caution when using sharp tools:** Always be aware of your surroundings and avoid making sudden movements.
* **Use a ladder safely:** If you need to reach high branches, use a sturdy ladder and have someone spot you.
* **Avoid pruning in wet weather:** Wet conditions can make surfaces slippery and increase the risk of accidents.
## Conclusion
Trimming overgrown boxwoods can seem like a challenging task, but with the right knowledge, tools, and techniques, you can successfully restore your boxwoods to their former glory. By following the steps outlined in this guide, you can improve the health, appearance, and longevity of your boxwoods and enjoy their beauty for years to come. Remember to assess your boxwoods carefully, use the appropriate pruning techniques, and provide proper post-pruning care. With a little patience and effort, you can transform your overgrown boxwoods into healthy and beautiful features of your landscape.