The western edge of Minnesota’s forest biome is known as the Hardwood Hills, and it includes all or parts of Becker, Clearwater, Douglas, Kandiyohi, Mahnomen, Meeker, Morrison, Otter Tail, Polk, Stearns, Todd and Wright counties.
The Hardwood Hills region is characterized by steep slopes, high hills and lakes, and acidic to alkaline, loamy soils. Pre-settlement vegetation ranged from tallgrass prairie to aspen, oak savannas, maple, basswood and other hardwood trees in fire-protected areas.
This list includes sugar maple, the primary producer of maple syrup, and bur oak, which is often found in many savanna and forest edge communities. The list also includes Dutch elm disease-resistant cultivars of American elm. The idea of reintroducing this iconic American tree to our forests is exciting, and it often does well in some of the same habitats as ash, which is not recommended because of emerald ash borer.
The list of recommended plants contains many wild edibles, including hog peanut, American hazelnut, black cherry, chokecherry, smooth sumac and wild grape.
Recommended trees and plants
*This species of red oak is most susceptible to oak wilt. Check your area’s current oak wilt risk.
**Due to Dutch elm disease, only plant disease-resistant varieties of American elm.
The following plants native to this region are also found further south. They should be well-equipped to adjust to our climate as it becomes warmer and wetter. These native plants also provide diverse benefits to microfauna, such as pollinators, other insects, birds and bats.
Creating climate refugia
Models of the state’s future climate may not favor the survival of some species you see in your woods today. However, that doesn’t mean these species don’t hold intrinsic ecological, cultural or economic value. You can work to retain these species in your landscape and protect them from the impacts of climate change by creating forest refugia.
Species in this region that may be most vulnerable to climate change, pests and diseases:
- Black ash (Fraxinus nigra), white ash (Fraxinus americana) and green ash (Fraxinus pennsylvanica) are projected to do well in warmer and wetter climates but are all extremely vulnerable to emerald ash borer. Black ash is a cultural and ecological keystone species in northern Minnesota and is an essential part of Minnesota’s forests. If ash is present in your woodland, learn more about managing ash woodlands in response to emerald ash borer.
- Balsam fir (Abies balsamea) is projected to be vulnerable to a changing climate in this ecoregion. Balsam fir provides many benefits to wildlife including moose and white-tailed deer, but also increases the fuel load for forest fires. In this region, consider diversifying stands with a large component of balsam fir to mitigate fire risk while maintaining the winter food source and thermal cover provided by balsam fir.
- Bigtooth aspen (Populus grandidentata) and quaking aspen (Populus tremuloides) are both projected to be vulnerable to a changing climate in this ecoregion. Both species regenerate by root suckering (sprouting), and these aspen stands provide many benefits to wildlife throughout their life cycle. Harvesting in gaps can also promote a diversity of species, age classes, and structures that will improve the resilience of the stand. Learn more about managing aspen forests.
- Slippery elm (Ulmus rubra) is also projected to do well but is susceptible to Dutch elm disease. With no disease-resistant cultivars of slippery elm currently available, landowners should be cautious in choosing where to encourage this species.
- Red pine (Pinus resinosa), jack pine (Pinus banksiana), and Eastern white pine (Pinus strobus) are iconic Northwoods species that are projected to be vulnerable to climate change in this region. Consider thinning existing pine stands to promote sufficient growing space. Harvesting in gaps can also promote a diversity of species, age classes, and structures that will improve the resilience of the stand. Eastern white pine is preferred by deer, so bud capping or tree tubes can help increase seedling survival. Preventative pruning can also help to protect young white pine trees from white pine blister rust. Learn more about managing red pine, jack pine, and white pine forests.
- Tamarack (Larix laricina), black spruce (Picea mariana), northern white cedar (Thuja occidentalis) and balsam fir (Abies balsamea) are common conifer species that are often found in wet areas such as bogs, as well as drier sites. These species are projected to be vulnerable to climate change in this region. Consider planting these species with a mix of climate-capable species (listed below) on cool, moist sites to promote diversity and improve resilience.
- Paper birch (Betula papyrifera) and yellow birch (Betula alleghaniensis) are both projected to be vulnerable to climate change in this region. Retain existing paper and yellow birch in diverse stands with a mix of species, age classes, and structures. Paper birch is shade intolerant and therefore prefers full sun, while yellow birch tolerates intermediate levels of shade. Consider thinning, single tree, or group selection harvests to improve the resilience of birch forests. Learn more about managing birch forests.
- American basswood (Tilia americana) is a critical component of Minnesota’s maple-basswood forests, also known as the Big Woods. This species is projected to be vulnerable to climate change in this region. Basswood prefers well-drained soils and can tolerate intermediate levels of shade. Consider managing existing basswood stands through thinning and/or single tree or group selection harvesting to improve the resilience of the stand. Learn more about managing northern hardwood forests.
Potential future tree species
As our climate changes, some tree species might be able to move into new areas as habitat becomes more suitable. Climate scientists with the USDA Forest Service have identified tree species with migration potential in the Hardwood Hills.
Planting species not historically found in the region does carry some risk. Before you plant, learn more about assisted migration strategies, and work with a forester or another natural resource professional to determine the best options for your land and goals.
Woodlands of Minnesota Handbook
The Minnesota Department of Natural Resources has created a series of woodland handbooks that provide landowners with information on their region’s conditions, frequent challenges, and advice on setting and reaching management goals. The Hardwood Hills handbook includes information on wildlife, plants, invasive species, geology, landscape and watershed management for this special region of west-central Minnesota.
Reviewed in 2024