Photo: MN DNR Facebook page

By Laura Durenberger-Grunow - Boreal Community Media - March 5, 2025

The Minnesota Department of Natural Resources (DNR) released the 2024 Forest Health Annual Report earlier this year, which revealed another significant surge in eastern spruce budworm damage, particularly in Cook, Lake, and St. Louis counties. The report, which utilizes aerial surveys and ground-level assessments, indicates the highest levels of defoliation since the 1960s, impacting nearly 665,000 acres in the region in 2023 and 712,000 acres in 2024. Since 2021, spruce budworm has affected over 1,330,000 acres, 90% of which are in St. Louis, Lake, and Cook counties. This outbreak has prompted increased concern among landowners and spurred collaborative efforts to mitigate the damage to forest health and reduce potential wildfire risk.

The spruce budworm outbreak cycle

Unlike non-native, invasive species, which cause damage when introduced without natural predators, the spruce budworm is native to Minnesota. Its populations naturally cycle every 30-40 years, with outbreaks lasting 6-10 years. During these periods, larvae defoliate balsam fir (their preferred food source), spruce, and other conifers. While these outbreaks are normal, the North Shore Forest Collaborative, an association of natural resource agencies, conservation organizations, and private landowners, states that “extensive fire suppression” over the last few decades has likely “exacerbated the outbreaks” due to a more significant amount of mature balsam firs and other conifer tree species. 

Last year, 712,000 acres of forest were affected by spruce budworm, with 33,400 acres experiencing significant tree mortality. While some tree species can survive defoliation (particularly healthy spruce trees), repeated infestations, combined with factors like drought, weaken and kill trees. This results in habitat loss, reduced timber resources, and increased wildfire risk from accumulated dead wood. According to the Minnesota Board of Water and Soil Resources Technical Training and Certification Program Coordinator Jon Sellnow, in an interview from 2020, "Spruce will have some tolerance, but balsam fir, when they get to a certain age, it’s nearly 100% mortality. Balsam firs' lower branches act like a ladder that allows small ground fires to quickly move into the canopy, causing larger, more destructive fires." 

In the fall of 2024, several wildfires broke out across northern Minnesota. In September, the US Forest Service issued a warning stating that the warm temperatures, drought conditions, and “high fuel loads due to spruce budworm affected trees - both standing and laying down, could increase fire danger and behavior” throughout northern Minnesota.

The Wood Lake Fire within the Boundary Waters Canoe Area Wilderness, which was first detected in September, was cited as burning in an area with “a significant amount of spruce budworm-infested balsam fir" and thick vegetation. 

The effects and impacts of the current spruce budworm outbreak cycle, already present, are likely to continue into 2025. In the 2024 Forest Health Annual Report, officials stated, "Spruce budworm will likely continue to cause extensive defoliation and mortality in Lake and Cook counties in the upcoming years.” Sarah Waddle, Cook County U of M Extension educator, has been working alongside forest educators to help keep Cook County landowners and concerned residents informed on the outbreak. 

Last year, she co-hosted multiple workshops on spruce budworm and has been meeting with forestry educators to discuss outreach opportunities for this year. Waddle told Boreal Community Media that as the spruce budworm outbreak continues for the next few years, landowners, residents, and visitors continue to be interested in the topic. When asked if the cycle has reached its peak, she said, “It is hard to say if the cycle of budworm has "peaked".... the population dynamics in an outbreak are impacted by a variety of factors including predation, weather, and food sources. I've read in some places that an outbreak will likely continue until there is mortality of a significant portion of the trees the budworm feeds on in a particular region, and read elsewhere that the outbreak subsides when populations of natural predators (other insects mainly) of the budworm larvae surge and overtake the budworm populations,” Waddle said. 

 Spruce budworm larvae. MN DNR

Management efforts

Organizations throughout Minnesota are implementing ongoing management strategies to address spruce budworm damage and improve forest health. These strategies focus on reducing dead wood, thinning tree stands, harvesting mature trees to restore natural forest composition (which typically lacks the dense balsam fir stands currently found in areas that have had decades of fire suppression), and replanting diverse species. Some examples of large-scale projects include: 

• Minnesota DNR: received funding from the Lessard-Sams Outdoor Heritage Council to diversify and regenerate budworm-impacted land throughout the state.
  
  

• US Forest Service - Superior National Forest: conducted work removing dead trees due to spruce budworm damage as part of the 15-year Tofte Landscape Project, located in the Tofte Ranger District in Lake County. According to the Forest Service, “The area has extensive spruce budworm damage, and the project will help reduce wildfire risk by removing diseased trees.” Management tasks include harvesting mature trees to create a “younger” forest, mechanical site preparation, mosaic burns (patchwork burning with alternatives in intensity and timing across an area), and more.
  
  

• US Forest Service: began work on the Blue Cascade Project - Spruce Budworm Response and Restoration in 2024 to create a more resilient ecosystem that can withstand future insect and disease impacts. This project is located in the Gunflint Ranger District, between Caribou Trail and Highway 14, beginning on the west end and moving eastward throughout the next few years.
  
  

• The Nature Conservancy (TNC): partnered with state and federal organizations to determine effective treatment options for biofuel reduction and restoration in spruce budworm infected areas that may “inform a strategy,” according to the North Shore Forest Collaborative. TNC plans to utilize this information moving forward when applying for funding that can be used on public lands.
  
  

• TNC: planted 2.3 million trees across partner lands in northern Minnesota in 2024 to increase the diversity and resiliency of those forests. 
  
  

As state and federal entities continue implementing management and treatment plans, local organizations are working to assist landowners and residents in various ways. 

Arrowhead Forest Partnership, EQIP, and the Cook County Soil and Water Conservation District

The US Department of Agriculture (USDA) manages a department called Natural Resources Conservation Services (NRCS). NRCS and five northeastern Minnesota Soil and Water Conservation Districts (SWCD), including Cook County, partner through the Arrowhead Forest Partnership (AFP). Through the AFP, local SWCDs facilitate landowner access to technical and financial assistance through a resource called the Environmental Quality Incentives Program (EQIP), which is offered through the NRCS. 

To simplify, the USDA manages the NRCS, which has a program called EQIP. The NRCS and five NE MN SWCDs partner through the AFP to help landowners access assistance offered through EQIP. 

Since 2018, the NRCS has contributed $1,142,235 through EPIQ, with local SWCDs assisting landowners in EQIP applications. According to Cook County SWCD Conservation Technician Stephen Janasie, NRCS reimburses SWCDs for their work on EQIP projects as part of the AFP agreement.

When it comes to receiving assistance through EQIP for spruce budworm management and treatment, Janasie said, “There is an application process that takes time and is competitive, but if a plan is accepted into the [EQIP], NRCS will provide payments for treatment on a per acre basis ($1,344.00/acre, or $1,612.00/acre if the landowner qualifies as historically underserved). The landowner hires a contractor to complete the treatment with oversight from NRCS, and if everything is completed to the agency’s satisfaction, reimbursement is made based on the current rate.”

Cook County SWCD Cost Share Program

Another way the Cook County SWCD can assist landowners is through a cost-share program through the organization, using funds set aside for conservation projects (including spruce budworm treatment). Janasie says, “The funds are limited, so we usually have more interest in projects than available funds. We do have to prioritize projects based on the natural resource concern.” 

If selected, the landowner signs a contract, which includes a plan for treatment, operation, and maintenance (usually a 10-year commitment) created by the SWCD, which also provides oversight to ensure the treatment is completed as agreed upon. “In most cases, we cover 75% of the project's cost, and the landowner is responsible for 25% of the cost,” he added. 

Cook County SWCD: Technical Assistance and Consultations

Any Cook County landowner can receive free technical assistance and consultation from the SWCD. Janasie said that SWCD staff will come out and conduct a free site visit. From there, staff will make recommendations to the landowner on next steps. “In some cases, [SWCD] guides them towards an EQIP application or a cost share agreement. However, in other cases, we simply provide technical recommendations, and the landowner takes that information and pursues treatment on their own, usually with the help of a private contractor,” he added.

Janasie acknowledges that all of the information and resources can seem complicated, “Which is one of the reasons the SWCD is here, to help navigate all of this.” If landowners are interested in a consultation, he recommends requesting one sooner rather than later. “We are a small office, so we typically have a wait list for forestry consultations…we can’t immediately respond to every concern due to capacity issues. We usually can get out to a site within a couple of months of initial contact, depending on whether or not we are in our field season.” 

Contact the Cook County SWCD at 218-387-3647 or email (which can be found on the website). 

Other local resources

Other local resources are available to guide landowners regarding forest health during the ongoing spruce budworm outbreak. Visit the websites below to learn more about each organization. 

• North Shore Forest Collaborative: Woods Walk Advisory Program

• Let’s Plant Trees: provides education on planting native trees and forest health and offers free seedlings in the spring

• U of M Extension: provides resources and information for at-home management strategies, including thinning or chemical controls

• Cook County U of M Extension & Cook County Higher Education: Spruce budworm webinar recordings

• MN DNR: management efforts for landowners