The emerald ash borer (EAB) continues its devastating march across Minnesota, threatening millions of ash trees throughout the Twin Cities and beyond. If you have ash trees on your property, fall 2025 represents a critical decision point: treat or remove? Understanding the timeline, costs, and options available can save you thousands of dollars and help preserve the trees that define your landscape.
The Current State of EAB in Minnesota
Since its first detection in Minnesota in 2009, the emerald ash borer has spread to over 30 counties, with confirmed infestations throughout the Twin Cities metro area. This metallic green beetle has already killed over 15 million ash trees in Minnesota, making it the most destructive forest pest in state history.
EAB Timeline in the Twin Cities
2009-2015: Initial detection and slow spread
2016-2020: Rapid expansion throughout metro area2021-2025: Widespread establishment in all Twin Cities counties
2025 and beyond: Focus shifts from prevention to management and replacement
The Minnesota Department of Agriculture estimates that untreated ash trees in infested areas have a 99% mortality rate within 4-6 years of initial EAB detection in the area.
Fall: The Critical Treatment Window
Fall represents your last best opportunity to effectively treat ash trees before winter. Here's why timing is everything:
Why Fall Treatment Matters
Systemic Insecticide Uptake
- Trees are actively translocating nutrients to roots for winter storage
- Soil-applied treatments have maximum uptake efficiency
- Treatment compounds concentrate in tree tissues before winter dormancy
Pre-Winter Protection
- Adult beetles are still active through early October in Minnesota
- Fall treatment protects against late-season egg laying
- Establishes protection for the following growing season
Cost Effectiveness
- Fall treatment rates are often lower than peak-season pricing
- Scheduling is more flexible than during spring rush
- Multi-year treatment programs can be established at optimal rates
Identifying Ash Trees on Your Property
Before determining your treatment strategy, you need to confirm which trees are ash species. Common ash trees in Minnesota include:
White Ash (Fraxinus americana)
- Compound leaves with 5-9 leaflets
- Diamond-patterned bark on mature trees
- Large, robust specimens common in established neighborhoods
Green Ash (Fraxinus pennsylvanica)
- Similar compound leaves but more tolerant of wet soils
- Smooth bark when young, becoming furrowed with age
- Most common ash species in Minnesota landscapes
Black Ash (Fraxinus nigra)
- Prefers wetland areas and poorly-drained soils
- Bark separates into thin, dark scales
- Less common in residential landscapes
Professional Identification: If you're unsure about species identification, Minnesota Landscapes' certified arborists provide free ash tree identification as part of comprehensive property assessments.
Signs of EAB Infestation
Early detection is crucial for treatment success. Watch for these warning signs:
Early Symptoms (Years 1-2)
- Crown dieback: Upper branches showing premature leaf drop or failure to leaf out
- Epicormic sprouting: Unusual growth of shoots from the trunk or main branches
- Bark splitting: Vertical cracks in bark, especially on the trunk
- Increased woodpecker activity: Birds creating holes while feeding on EAB larvae
Advanced Symptoms (Years 2-4)
- D-shaped exit holes: 1/8-inch holes in bark where adult beetles emerged
- S-shaped galleries: Serpentine patterns under bark created by feeding larvae
- Significant canopy thinning: More than 50% branch dieback
- Bark falling off: Loose bark reveals gallery patterns underneath
Critical Point: Once trees show advanced symptoms, treatment success rates drop significantly, and removal may be the only safe option.
Treatment Options and Effectiveness
Emamectin Benzoate (TREE-äge)
Application Method: Professional trunk injection
Protection Duration: 2-3 years per treatment
Effectiveness: 95%+ protection when applied to healthy trees
Cost: $8-15 per diameter inch
Best For: High-value trees with minimal EAB symptoms
Advantages:
- Longest protection period
- Highest effectiveness rate
- No soil contamination
- Immediate systemic distribution
Considerations:
- Requires professional application
- Higher upfront cost
- May cause temporary canopy stress
Imidacloprid Treatments
Application Method: Soil drench or trunk injection
Protection Duration: 1-2 years per treatment
Effectiveness: 70-85% protection on healthy trees
Cost: $3-8 per diameter inch
Best For: Preventive treatment of uninfested trees
Advantages:
- Lower cost per treatment
- Multiple application methods available
- Established track record
Considerations:
- Annual or biennial retreatment required
- Reduced effectiveness on stressed trees
- Potential environmental concerns
DIY Treatment Options
While professional treatment is most effective, some homeowner-applied products are available:
Bayer Tree & Shrub Insect Control
- Active ingredient: Imidacloprid
- Application: Soil drench around tree base
- Cost: $20-40 per treatment
- Effectiveness: 60-75% when properly applied
Important Note: DIY treatments are only recommended for smaller trees (under 15 inches diameter) and require precise application timing and rates.
The Treatment vs. Removal Decision Matrix
Treat If:
- Tree diameter is 6 inches or larger
- Less than 30% crown dieback present
- No significant structural issues
- Tree provides significant landscape or property value
- Treatment cost is less than 50% of replacement value
Remove If:
- More than 50% crown dieback evident
- Structural integrity compromised
- Located near structures, power lines, or high-traffic areas
- Treatment cost exceeds replacement value
- Multiple treatments have failed
Economic Considerations
Treatment Costs (10-year period):
- Small tree (6-12" diameter): $200-600 total
- Medium tree (12-20" diameter): $400-1,200 total
- Large tree (20"+ diameter): $800-2,500 total
Removal and Replacement Costs:
- Removal: $500-2,000 per tree
- Stump grinding: $100-300 per stump
- New tree and installation: $200-1,000
- Total replacement cost: $800-3,300 per tree
Geographic Risk Assessment in the Twin Cities
High-Risk Areas
Areas with confirmed EAB activity and high ash tree populations:
Minneapolis/St. Paul Urban Core
- Established EAB populations since 2015
- High density of mature ash trees
- St. Paul and Minneapolis have active EAB management programs
First-Ring Suburbs
Emerging Risk Areas
Areas where EAB is newly detected or spreading:
Outer Suburbs
- Apple Valley, Eagan, and Woodbury seeing increasing detection
- Treatment still highly effective in these areas
- Proactive management recommended
Rural Edge Communities
Fall Treatment Timeline
September: Assessment and Planning
- Week 1-2: Professional assessment of all ash trees
- Week 3-4: Treatment vs. removal decisions
- Late September: Begin scheduling treatments and removals
October: Peak Treatment Window
- Early October: Soil temperature ideal for systemic uptake
- Mid-October: Last opportunity for most treatment types
- Late October: Emergency treatments only (reduced effectiveness)
November: Final Actions
- Early November: Complete any remaining treatments
- Mid-November: Begin removal of condemned trees
- Late November: Winter prep for treated trees
Critical Deadline: Most treatments must be completed by October 15th for optimal effectiveness in Minnesota's climate.
Professional vs. DIY: Making the Right Choice
When Professional Treatment Is Essential
Large Trees (15"+ diameter)
- Require specialized injection equipment
- Higher treatment volumes need precise calculation
- Safety concerns with trunk injection procedures
High-Value Landscapes
- Treatment failure costs are too high to risk
- Professional warranty and guarantee programs available
- Integrated management with other tree care services
Multiple Tree Properties
- Volume discounts make professional treatment cost-effective
- Coordinated treatment timing ensures maximum effectiveness
- Long-term management planning prevents future crises
Professional Treatment Advantages
Minnesota Landscapes' EAB Treatment Program includes:
Comprehensive Assessment
- Individual tree health evaluation
- EAB detection and damage assessment
- Treatment vs. removal recommendations
- Cost-benefit analysis for each tree
Professional-Grade Products
- Access to restricted-use pesticides unavailable to homeowners
- Proven formulations with highest effectiveness rates
- Proper application equipment and techniques
Warranty Protection
- Treatment effectiveness guarantees
- Follow-up monitoring and assessment
- Retreatment if EAB breakthrough occurs
Ongoing Management
- Multi-year treatment scheduling
- Annual monitoring for EAB activity
- Integration with overall tree care programs
Alternative Species for Ash Replacement
If removal is the best option for your ash trees, consider these Minnesota-hardy alternatives:
Similar Size and Shape
American Elm (Disease-Resistant Cultivars)
- 'Valley Forge', 'Princeton', 'New Harmony'
- Similar vase shape to ash
- Dutch elm disease resistant
Hackberry (Celtis occidentalis)
- Native Minnesota species
- Tolerates urban conditions
- Similar size potential to ash
Fast-Growing Options
Red Oak (Quercus rubra)
- Excellent fall color
- Long-lived and durable
- Slower establishment but superior longevity
Sugar Maple (Acer saccharum)
- Outstanding fall color
- Minnesota native
- Shade tolerance for understory planting
Recommendations based on location: Contact our design team for site-specific replacement recommendations throughout the Twin Cities area.
Cost-Saving Strategies
Multi-Year Treatment Programs
- 15-20% savings with 3-year treatment commitments
- Guaranteed scheduling and pricing
- Coordinated application timing
Neighborhood Group Programs
- Volume discounts for multiple properties
- Reduced mobilization costs
- Coordinated treatment schedules
Integrated Services
- Combine EAB treatment with fall pruning
- Bundle with other tree health services
- Multi-tree maintenance contracts
Emergency Indicators: When Time Is Critical
Call immediately if you observe:
Rapid Decline
- Sudden leaf drop or wilting in late summer
- Extensive bark splitting or falling
- Heavy woodpecker damage appearing quickly
Safety Concerns
- Large dead branches over structures
- Leaning or unstable trunk
- Multiple trunk failures on neighboring ash trees
Infrastructure Threats
- Trees over power lines showing decline
- Ash trees threatening roadways or walkways
- Root damage from construction affecting stability
Taking Action: Your Next Steps
Immediate Actions (This Week)
- Identify all ash trees on your property using identification guides
- Assess current condition looking for EAB symptoms
- Contact professionals for comprehensive evaluation
- Document tree locations and conditions with photos
Short-Term Planning (Next 30 Days)
- Schedule professional assessment with certified arborists
- Obtain treatment quotes from multiple qualified providers
- Make treatment vs. removal decisions based on professional recommendations
- Begin treatment scheduling for optimal timing
Long-Term Management (This Fall and Beyond)
- Complete treatments by mid-October deadline
- Plan replacement trees for removed ash specimens
- Establish monitoring schedule for treated trees
- Budget for ongoing management in subsequent years
Why Choose Minnesota Landscapes for EAB Management
With over two decades of experience serving the Twin Cities, Minnesota Landscapes brings unmatched expertise to EAB management:
Certified Expertise
- ISA-certified arborists with EAB specialization
- Minnesota Department of Agriculture licensed applicators
- Ongoing education in latest treatment protocols
Comprehensive Services
- Assessment and diagnosis of EAB infestation levels
- Professional treatment programs using industry-leading products
- Safe removal services for compromised trees
- Replacement planning and installation with EAB-resistant species
Local Knowledge
- Deep understanding of EAB progression in Twin Cities area
- Site-specific recommendations based on neighborhood conditions
- Integration with city and county EAB management programs
Service Area Coverage
Professional EAB services available throughout the Twin Cities metro, including Eden Prairie, White Bear Lake, Mendota, and all surrounding communities.
Don't Wait: The Cost of Delay
Every month you delay EAB treatment increases the risk of:
- Treatment failure due to advanced infestation
- Emergency removal costs if trees become hazardous
- Property damage from failing ash trees
- Increased treatment costs as infestation spreads
The window for effective EAB management is closing. Trees showing early symptoms today may be untreatable by spring 2026.
Schedule Your EAB Assessment Today
Call 651-457-0000 for immediate consultation with our experts, or book online for convenient scheduling.
.png)
