Hedge Trimming FAQ: 18 Common Questions Answered by a Certified Arborist

1. Why is hedge trimming important? 

Hedge trimming is important for both plant health and appearance. Regular trimming removes dead, damaged, or diseased growth, allowing sunlight and airflow to reach the interior of the hedge. This promotes healthier growth, reduces pest and disease pressure, and helps maintain a consistent shape and size. Properly maintained hedges can also improve privacy, reduce noise, and act as wind buffers for homes in the Seattle area.

2. When is the best time to trim hedges? 

The best time to trim hedges depends on the species, but most hedges are best trimmed during their dormant period in late winter or early spring, before new growth begins. Trimming during dormancy minimizes stress on the plant and encourages strong, healthy regrowth in the spring.

Flowering hedges should generally be trimmed after they bloom, so flower buds are not removed. In the Pacific Northwest, timing should also account for weather conditions, soil moisture, and local wildlife considerations.

It's also essential to consider any local regulations or restrictions on trimming during certain times of the year. For most homeowners, late winter to early spring remains the safest and most effective time to trim hedges.

3. What is the best time of year to trim hedges?

For most hedges, the best time of year to trim is late winter to early spring, followed by light maintenance trimming in mid to late summer if needed. Evergreen hedges often tolerate light summer trimming well, while deciduous hedges respond best to structural pruning during dormancy. Avoid heavy trimming during extreme heat, drought, or freezing conditions.

4. Is the timing different for evergreen vs deciduous hedges?

Yes. Evergreen hedges are typically more tolerant of light, frequent trimming throughout the growing season, while deciduous hedges benefit from structural trimming during dormancy. Heavy pruning of deciduous hedges during active growth can stress the plant and reduce vigor, especially in urban environments with compacted soils.. 

5. How often should I trim my hedges?

Most hedges require trimming once or twice per year, depending on the species and desired appearance. Fast-growing hedges may need more frequent maintenance, while slow-growing or formal hedges may require less. Regular monitoring helps prevent excessive growth and reduces the need for aggressive cutting later.

6. What is professional hedge trimming?

Professional hedge trimming involves proper plant identification, timing, and pruning techniques performed by trained professionals. Unlike casual trimming, professional hedge trimming focuses on long-term plant health, correct tapering, species-specific growth habits, and safety considerations such as working near structures, slopes, or power lines. Professional hedge trimming involves proper plant identification, timing, and pruning techniques performed by trained professionals, often guided by arboricultural best practices.

7. When should you hire a professional for hedge trimming?

You should consider hiring a professional when hedges are tall, overgrown, near utilities, or require corrective or restorative pruning. Professional assistance is also recommended when improper trimming could permanently damage the hedge or create safety hazards.

8. Is professional hedge trimming worth it?

Professional hedge trimming is often worth it for larger or more complex hedges. Proper technique helps prevent long-term decline, uneven growth, and structural failure. It also reduces the risk of injury and ensures the hedge maintains its intended form and function over time.

9. What tools are needed for hedge trimming?

Common hedge trimming tools include sharp hedge shears, hand pruners, loppers, and pruning saws for thicker branches. Safety equipment such as gloves, eye protection, and stable ladders is also essential. For tall or dense hedges, specialized equipment and training may be required.

10. What is the proper way to trim a hedge?

Proper hedge trimming begins with removing dead or damaged branches. The sides and top should then be shaped using long, sweeping motions to create clean lines. A slight taper—wider at the base and narrower at the top—ensures sunlight reaches the lower foliage. Avoid removing too much growth at once, and follow the one-third rule to minimize stress.

11. Do you trim hedges from top to bottom or bottom to top?

Hedges are typically trimmed from the bottom up. This method helps maintain proper tapering and prevents cut debris from interfering with lower branches. Working upward also improves visibility and consistency.

12. Does trimming the top of a hedge make it grow thicker?

Yes. Trimming the top of a hedge encourages lateral growth, causing the hedge to fill out and become denser. This is especially useful for privacy hedges when done correctly and at the appropriate time of year.

13. Should cuts be made above or below a node?

Cuts should be made just above a node. Cutting above a node encourages new growth in the desired direction and reduces the likelihood of dieback.

14. Can hedge trimming be done at any height?

Hedge trimming can be performed at any height, but safety should always be the priority. Tall hedges may require ladders, climbing equipment, or specialized tools. When hedges are near power lines or on slopes, professional assistance is strongly recommended.

15. How do I rejuvenate an overgrown hedge?

Rejuvenating an overgrown hedge requires a gradual approach. Instead of removing excessive growth all at once, trimming should be spread over two to three seasons. This allows the plant to recover and promotes healthy regrowth without excessive stress.

16. How much can I cut off the top of my hedge?

In most cases, no more than one-third of the hedge’s total growth should be removed in a single season. Removing more than this can weaken the plant and increase the risk of decline or failure.

17. What safety precautions should I take when trimming hedges?

Wear protective gear such as gloves, eye protection, and sturdy footwear. Ensure ladders are stable and placed on level ground. Be aware of overhead hazards, including power lines and wildlife habitats, and avoid trimming during unsafe weather conditions.

18. Can I trim hedges myself, or should I hire a professional?

Small, low hedges can often be trimmed safely by homeowners with the proper tools and knowledge. Larger, taller, or more complex hedges are best handled by professionals who have the training and equipment to perform the work safely and correctly.

Conclusion

You are now armed with expert answers to the most common hedge trimming questions, including timing, technique, safety, and when to consider professional hedge trimming. Remember to trim at the appropriate time, use proper techniques and tools, prioritize safety, and seek professional help when needed. 

With the right care and attention, your hedges will thrive, adding beauty and functionality to your property for years.

If you need assistance or expert advise on how to trim and care for your particular hedge, we have a certified arborist and offer tree care consultations and hedge trimming services to the greater Seattle area.