Plant by Habitat: Oak Savanna

Recently I posted information about native Oaks and later realized it might be helpful to have some information not just about which plants are native vs invasive, but it may also be helpful to have some sense of which native plants actually grow together naturally. Over the next couple of weeks, I'll do some "Plant by Habitat" posts to hopefully help inform decisions about which native plants to purchase together.

The Oak Savanna is a type of habitat which features large Oaks with room to really spread their limbs. These savannas were once found throughout the Midwest and served as the boarder between the prairies and grasslands of the Great Plains and the forests of the Eastern United States. A variety of Oak species were found in the savannas including: Black Oak, Bur Oak, Northern Red Oak, and White Oak. These trees can be found commercially available, and if you are interested in planting your own Oak Savanna, an Oak is a good place to start.

That said other trees and plants could be found in the savannas. Shagbark Hickory and Black Cherry are also excellent savanna trees to consider. Black Cherry is particularly interesting as it is a host for a variety of caterpillars and its fruit is eaten by many birds.

Once you've selected your trees, you are on to deciding what will go in the understory. You will need to decide exactly how wide open your savanna will be. Some savannas would have had some shrubby understory if less frequented by fire, but those more frequented by fire would have had more prairie grasses and flowers.

Highbush Cranberry can be really attractive in the fall.

My favorite shrubs to consider are Viburnums. American Highbush Cranberry, Nannyberry, and Mapleleaf Viburnum are interesting choices. Viburnums tend to be pretty tolerant of most growing situations, have attractive foliage in the fall, and they tend to be pretty easy to find commercially. These are really great shrubs, we have 4 Highbush Cranberries and 2 Nannyberries in our yard. Pagoda Dogwood, Hazelnut, and Staghorn Sumac are also good choices. The Sumac and the Dogwood are fairly shade tolerant, so they may not be best suited to an open savanna habitat, they do however produce fruit which can be eaten by birds. The Hazelnut will produce nuts which fall to ground and are eaten by mammals like Gray, Red, or Fox Squirrels but also by Wild Turkey and Ruffed Grouse.

By this point, you have a tree or two selected; you've decided on a shrub or two, and now you need something to cover the ground. You are now looking for plants which do well when burned back semi-regularly. You are going to want some prairie grasses, some of the easiest species to acquire are Little Blue Stem, Big Blue Stem, and Prairie Dropseed. The flowers for an Oak Savanna can be more difficult to find but they include plants loved by butterflies such as Purple Milkweed and Common Milkweed. Shooting Star, Wild Indigo, and Wild Columbine are also reasonably easy to find as plugs or seeds.

We put in a few indigo plants last year which were not by the rabbits.

With these plants in place, a lawn would be replaced with a small Oak Savanna. It would be fairly biodiverse in terms of plants species and be able to support a number of bird and butterfly species. If you live in the Midwest (see map), there is a reasonable chance your yard was once in fact part of the Oak Savannas. The Oak Savannas were replaced with farmland and then the farmland with subdivisions, so why not give part of your yard back and return it to nature, after all the birds and the butterflies are the ones who have to live with it.