Tree Spades Mounted on Excavators: Enhancing Transplanting Efficiency

[MikePhua]

Overview of Tree Spades on Excavators
Tree spades are specialized attachments designed to excavate and transplant trees with minimal root disturbance. Traditionally, they have been mounted on dedicated tree spade vehicles or skid steers. However, the trend of mounting tree spades on excavators has gained traction due to the excavator’s versatility and reach, enabling landscapers, nurseries, and municipal crews to work more efficiently in diverse terrain and tight spaces.
A tree spade consists of several curved steel blades arranged in a circular pattern around the tree trunk. These blades penetrate the ground to cut and lift the root ball, which is then transported and replanted.
Benefits of Using Tree Spades on Excavators

• Enhanced Mobility and Reach
  Excavators offer superior boom articulation, allowing the operator to maneuver the tree spade in confined or uneven areas where wheeled vehicles struggle.
  
• Versatility of the Excavator Base Machine
  Beyond tree spading, the excavator can be quickly switched to other attachments (buckets, grapples), maximizing equipment utilization.
  
• Increased Stability
  The tracked undercarriage of excavators provides better stability on slopes or soft ground compared to wheeled carriers.
  
• Higher Digging Force
  Excavators typically offer greater hydraulic flow and digging force, enabling faster penetration of hard or compacted soils.
  

Key Considerations for Tree Spade Excavator Integration

1. Hydraulic Compatibility
   The tree spade attachment requires sufficient hydraulic flow and pressure, often demanding auxiliary hydraulic circuits on the excavator. Flow rates of 20 to 40 gallons per minute and pressure ratings of 3,000 to 4,000 psi are common.
   
2. Mounting System
   Tree spades for excavators generally use quick couplers or custom mounts. Ensuring secure attachment and proper hydraulic hose routing is critical to avoid damage during operation.
   
3. Size and Capacity
   Tree spades come in various diameters, typically ranging from 24 to 60 inches. Matching the spade size to the excavator’s class and tree size ensures effective digging without overloading the machine.
   
4. Operator Training
   Operating a tree spade on an excavator requires skill to precisely position the blades around the tree and control soil penetration without damaging roots.
   

Common Challenges and Solutions

• Hydraulic Overload
  Some excavators lack the hydraulic capacity for larger tree spades. Installing high-flow auxiliary pumps or using flow dividers can alleviate this.
  
• Attachment Weight and Balance
  The tree spade adds weight at the boom’s end, affecting balance and potentially reducing lift capacity. Counterweights or boom limiters may be necessary.
  
• Blade Wear and Maintenance
  Tree spade blades are subject to abrasive wear. Regular inspection, sharpening, and replacement of blades ensure clean cuts and efficient digging.
  

Case Studies and Practical Applications
A landscaping company in Oregon retrofitted a mid-sized excavator with a 36-inch tree spade to streamline urban tree relocations. The setup reduced transplant time by 40% compared to manual digging, minimized root damage, and allowed access to tight city sites. Operators reported the excavator’s superior reach and stability as game changers.
In another instance, a nursery in Georgia used a tracked excavator with a 48-inch tree spade to dig and load large saplings onto transport trailers efficiently. The hydraulic demands were met by upgrading the excavator’s auxiliary circuit, enabling continuous operation without overheating.
Terminology Glossary

• Tree Spade: A circular blade attachment designed for digging and transplanting trees with their root balls intact.
  
• Auxiliary Hydraulics: Additional hydraulic circuits on equipment used to power attachments.
  
• Quick Coupler: A device that allows fast attachment changes on excavators.
  
• Root Ball: The soil and roots surrounding a tree, preserved during transplanting.
  

Conclusion
Mounting tree spades on excavators merges the precision and power of hydraulic excavators with the specialized function of tree transplanting tools. This combination enhances operational flexibility, reduces manual labor, and increases the success rate of tree relocations. While there are challenges involving hydraulics, balance, and operator skill, these can be effectively managed with proper equipment selection and maintenance. As environmental consciousness grows and urban forestry expands, excavator-mounted tree spades are poised to become standard tools in landscaping and municipal operations worldwide.