The Oak Savanna subsection includes all or parts of Dakota, Dodge, Fillmore, Freeborn, Goodhue, Le Sueur, Mower, Olmsted, Rice, Steele and Waseca counties.

Much of this area is a rolling plain of windblown, silt-covered ridges over sandstone and carbonate bedrock and till. Soils range from wet to well-drained, formed under prairie or forest conditions. Original vegetation included bur oaks, maples, basswood and prairie tall grasses.

The following species are not currently native to Ecoregion 8, but this region's future climate may be suitable  to support habitat for these species. Extension Forestry is interested in learning more about these species, and we want to know if any of these species are already present on the landscape in Region 8. Learn more about each species using the drop-down buttons below.

Photo by MN DNR

Black hickory is native to the central U.S. primarily in Missouri and Arkansas, with the northern end of its range extending into Illinois. It is a small to medium sized tree, with 5-7 leaflets per compound leave. The bark is not shaggy like other hickories, and is dark gray and coarsely rough-textured.  Like other hickories, black  hickory supports many species of insects, mammals, and birds. It's hardy to zones 5-9. Learn more about black hickory on the Illinois Wildflowers page.

Photo by Brenda K. Loveless, Wildflower Center Digital Library

Mockernut hickory, also know as white hickory, has mostly white wood and leaves similar to the other hickories. The species epithet "tomentosa" (covered in hair) refers to the fuzzy stems near the buds.It produces edible nuts for up to 200 years, and provides habitat to many species of wildlife, including many butterflies and moths. Mockernut hickory is native to much of the eastern, central, and southeastern U.S. It is hardy to zones 4-9. Learn more about mockernut hickory on the NC State Extension Horticulture page.

Photo by Vern Wilkins, Indiana University, Bugwood.org

This small understory tree that has conspicuous small purple flowers along the stem in early spring. It's considered hardy from plant zones 4a-9b. To learn more about this species and how to identify it visit the NC State Extension Horticulture page or the University of Wisconsin-Madison Extension website. This tree is not considered native to Minnesota and is planted in some communities including Rochester and the Twin Cities.

Photo from iNaturalist by m_whitson 

Common persimmon is native to the central and eastern U.S. and is hardy to zones 4-9. It produces delicious fruit in the fall, which provides food for wildlife as well as humans. A key feature of this species is the lack of terminal buds on the branches, since the tree never goes dormant. This species also has checkerboard-like bark that can be used for identification. Learn more about common persimmon on the NC State Extension Horticulture page. 

Photo from iNaturalist by laalv1

Osage-orange is a medium sized tree with large baseball size yellow-green, inedible, fruit on female trees. The name is derived from this orange-like fruit. The leaves are simple, elongated egg-shaped with smooth edges. Thorns form below the leaves on new shoots. The bark is furrowed, orange-brown to gray-brown with an irregular criss-crossed pattern. It is considered hardy from plant zone 4-9. To learn more about this species and how to identify it visit the NC State Extension Horticulture page or the UMN website.

Photo from iNat by mariposa21157

Sycamore is a large deciduous tree with reddish brown, scaly bark at the base that appears white nearer to the crown. The leaves look similar to grape leaves, and the twigs are zig-zag patterned. It produces large spherical fruit. Sycamore is native across the eastern U.S. and its northern range extends into Iowa. It's hardy to zones 4-9. Learn more about sycamore on the NC State Extension Horticulture page.

Photo by Rob Routledge, Sault College, Bugwood.org

Swamp white oak is a large overstory tree that is native to southeast MN and much of the eastern and central U.S.  As a member of the white oak group, swamp white oak has rounded lobes, but not nearly as deeply divided as white oak. Some of the leaves on swamp white oak can resemble a diamond in shape. The undersides of swamp white oaks are light green and slightly hairy. Swamp white oak is hardy to zones 3-8. Learn more about swamp white oak on the UMN website.

Forest health threat: Swamp white oak is susceptible to oak wilt, a fungal pathogen that kills oaks. Oak wilt kills white white oaks are less quickly than red oaks (such as northern red oak and northern pin oak).

Photo by Paul Wray, Iowa State University, Bugwood.org

Shingle oak is native to the eastern and central U.S. and is hardy to zones 4-8. It develops a round or conical form. Its leaves are glossy, leathery and elliptical in shape, unlike other oaks. Regardless of this difference in appearance, this oak is in the red oak group of oaks, similar to MN's northern red oak. Learn more about shingle oak on the NC State Extension Horticulture page. 

Forest health threat: Shingle oak is very susceptible to oak wilt, a fungal pathogen that kills oaks. Oak wilt kills red oaks more rapidly than white oaks. 

Photo by Richard Webb, Bugwood.org

Chinkapin oak is a tree is the white oak group, but its leaves look chestnut-like in appearance. The leaves are diamond-shaped and are toothed with shallow lobes. Chinkapin oak is native across the eastern U.S., including the far southeast corner of MN. It's considered hardy to zones 3-7. Learn more about chinkapin oak on the NC State Extension Horticulture page.

Forest health threat: Chinkapin oak is susceptible to oak wilt, a fungal pathogen that kills oaks. Oak wilt kills white white oaks are less quickly than red oaks (such as northern red oak and northern pin oak).

Photo by Paul Wray, Iowa State University, Bugwood.org

Pin oak (not to be confused with northern pin oak, Quercus ellipsoidalis) is native to to the northeast and east-central U.S. It has 5 bristle-tipped lobes with deep U-shaped sinuses. The acorns are round with a thin smooth cap. Learn more about pin oak on the UMN website or the NC State Extension Horticulture page.

Forest health threat: Pin oak is very susceptible to oak wilt, a fungal pathogen that kills oaks. Oak wilt kills red oaks more rapidly than white oaks. It's hardy to zones 4-8. 

Photo by David Cappaert, Bugwood.org

Post oak is a species in the white oak group that is native to much of the eastern and southeastern U.S. The leaves can be distinguished from other white oaks by the two middle lobes that are square-shaped, which gives the leaves a cross-like appearance. Post oak is hardy to zones 5-9. Learn more about post oak on the NC State Extension Horticulture page.

Forest health threat: Post oak is susceptible to oak wilt, a fungal pathogen that kills oaks. Oak wilt kills white white oaks are less quickly than red oaks (such as northern red oak and northern pin oak).

Photo by Chris Evans, University of Illinois, Bugwood.org

Sassafras is an aromatic, medium-sized tree. The leaves are alternately arranged and variable with smooth edges shaped as ovals, mittens or three lobbed. It is considered hardy from plant zone 4a-9b. To learn more about this species and how to identify it visit the NC State Extension Horticulture page.

Photo from iNat by vis5121.