The Importance of root flares

Exposing a tree's root flare is essential for the tree's health, longevity, and proper growth. The root flare, also known as the root collar, is the area where the trunk transitions to the roots and naturally flares out at the base of the tree. Here's why this is so important:

1. Prevents Rot and Decay

• When the root flare is buried under soil or mulch, the trapped moisture can lead to bark rot. This can weaken the tree's structure and create an entry point for diseases, pests, and fungi.

2. Allows Proper Gas Exchange

• Trees need to "breathe" through their root systems. If the root flare is buried, the roots can become oxygen-starved, leading to poor health and potential root dieback.

3. Encourages Strong Root Development

• When the root flare is exposed, it promotes the development of strong, healthy roots at the appropriate depth. Buried flares often cause roots to grow upwards or circle the trunk, leading to girdling roots, which can choke the tree and impede the flow of water and nutrients.

4. Prevents Stem Girdling

• A buried root flare can encourage girdling roots, where roots encircle and strangle the tree trunk. This compromises the structural integrity of the tree and can ultimately kill it.

5. Aids in Pest and Disease Prevention

• Many pests and diseases thrive in moist, dark environments. Keeping the root flare exposed minimizes these risks and allows for early detection of potential issues.

6. Supports Natural Stability

• The root flare acts as a natural anchor point for the tree, stabilizing it in the soil. When buried, the stability can be compromised, making the tree more vulnerable to uprooting in strong winds or storms.

7. Improves Aesthetic Appeal

• An exposed root flare enhances the natural beauty of a tree, giving it a healthy and well-maintained appearance.

Image Courtesy of University of Maryland

Best Practices for Exposing the Root Flare:

• Remove Excess Soil or Mulch: Gently excavate the soil or mulch around the base of the tree until the root flare is visible.

• Avoid Over-mulching: Keep mulch at least a few inches away from the trunk and root flare, and limit the depth of mulch to about 2-4 inches.

• Inspect When Planting: Ensure the root flare is at or slightly above ground level when planting. Avoid planting trees too deeply.

• Correct Girdling Roots: If girdling roots are present, consult a certified arborist to address the issue.

By exposing the root flare, you help ensure the tree's structural integrity, health, and longevity, fostering a thriving landscape.

The knowledge gap between nurseries (and their planting/install crews) and certified arborists regarding proper tree planting techniques often stems from differences in training, priorities, and roles in the tree care industry. Here's a breakdown of the main reasons:

1. Focus on Sales vs. Tree Health

• Nurseries: The primary focus of most nurseries is on growing, selling, and delivering trees, not necessarily ensuring their long-term survival after planting. Their staff may be trained in inventory management and basic plant care but may lack in-depth knowledge of arboriculture.

• Arborists: Certified arborists are trained to prioritize tree health and longevity. Their work goes beyond planting to include ongoing care, diagnosing issues, and ensuring trees thrive in their environments.

2. Lack of Specialized Training

• Nurseries: Staff and planting crews at nurseries typically receive on-the-job training focused on efficiency and speed, not the detailed science of tree health. They may not fully understand how improper planting (e.g., planting too deep or not exposing the root flare) affects a tree's long-term health.

• Arborists: Arborists undergo rigorous training and certifications, such as the ISA (International Society of Arboriculture) program, where they learn about proper planting techniques, soil science, root systems, and common pitfalls to avoid.

3. Emphasis on Aesthetics Over Function

• Nurseries: Nurseries often cater to customer preferences for quick, visually appealing results. They might plant trees with root flares buried or use improper staking techniques because it "looks good" temporarily.

• Arborists: Arborists focus on the tree's functional health and growth over its lifetime. They prioritize exposing the root flare, proper staking (or avoiding it when unnecessary), and planting at the correct depth.

4. Time and Cost Constraints

• Nurseries: Efficiency is key for nurseries to stay profitable. They often work on tight schedules and budgets, which can lead to shortcuts, such as planting trees too deeply, leaving containerized roots bound, or neglecting soil amendments.

• Arborists: Arborists tend to charge more for planting but spend more time on the process. They ensure proper site preparation, root pruning, soil testing, and other critical steps that nurseries may overlook.

5. Lack of Site-Specific Expertise

• Nurseries: Nursery staff may not evaluate site-specific conditions like soil type, drainage, or exposure to environmental stresses, leading to improper planting practices or tree species that are poorly suited to the location.

• Arborists: Arborists assess the site carefully, considering factors like soil compaction, water drainage, and local pests or diseases to ensure the tree's success.

6. Limited Knowledge of Long-Term Issues

• Nurseries: Many nursery crews are unaware of how improper planting (like girdling roots or excessive mulching) causes long-term health problems. Their responsibility often ends after the tree is delivered and planted.

• Arborists: Arborists understand that planting errors may not become evident for years. They aim to prevent problems like root girdling, decay, and poor structural development from the start.

7. Certification and Regulation Differences

• Nurseries: In many areas, nursery staff and installers are not required to hold certifications in tree care. Their expertise may vary widely based on individual training or company practices.

• Arborists: Certified arborists adhere to industry standards, such as ISA and ANSI A300 for planting and tree care, which promote the best practices for tree health and stability.

Why This Matters to You as a Consumer

Improper planting can lead to significant costs down the line, including tree replacement, structural damage, or safety hazards. Hiring a certified arborist for tree planting or consulting with one before purchasing a tree from a nursery ensures that:

• Trees are planted correctly.

• Proper species are selected for the site.

• The investment in your landscape is protected.

By bridging the gap between nursery practices and arborist expertise, you can help ensure the long-term health and success of your trees.

Hiring a qualified professional, such as a certified arborist, to install your trees is essential for ensuring their long-term health, stability, and growth. While nurseries may focus on efficiency and aesthetics, arborists bring specialized knowledge of proper planting techniques, such as exposing the root flare, avoiding girdling roots, and planting at the correct depth. Arborists also evaluate site-specific factors like soil conditions, drainage, and species suitability, which nurseries often overlook. Investing in a professional ensures your trees are set up for success, reducing future costs from preventable issues like decay, pest infestations, or tree failure. Ultimately, their expertise protects your investment and contributes to a thriving, sustainable landscape.