The term "deciduous" refers to trees that lose their leaves each autumn and grow new ones each spring. They are also called "hardwood" or "broad-leaved" trees. They include the familiar oaks, elms, maples, aspens, and ashes. They are the predominate tree type in southern and central Minnesota.

Forests made up entirely of deciduous trees are called deciduous forests, but they can vary greatly in the composition of tree species and the soil and moisture conditions under which they occur. As a general rule, oaks are more common on drier soils, while maples, aspens, and ashes are more common on moister soils.

Because of widespread logging and land clearing in Minnesota, most of the state's deciduous forests are second-growth, relatively young forests. While these young forests provide habitat for common animal and plant species, many of the state's rarer animals and plants depend on deciduous forests with old trees, large standing dead trees or "snags", and large decaying logs on the forest floor.