Cumberland Rosemary

Photo by Zach Irick, SGI Southern Appalachian Grasslands Ecologist and Partner, Cumberland Piedmont Inventory & Monitoring Network

Scientific Description: Cumberland Rosemary – Conradina verticillata – is a deciduous, perennial short shrub and a member of the Mint (Lamiaceae) family. Currently, this species is on both the Tennessee and federal protection lists classified as Threatened. However, a variety is propagated commercially and, therefore, can be grown in our gardens. Wild specimens are protected because of habitat destruction.

This plant rarely grows taller than 2 feet and produces pink to purple flowers with reddish spots inside the flower throat from May through June. The leaves are needle-like. 

Cumberland Rosemary is only found in the wild in Kentucky and Tennessee. The specimens that are from commercial growers are ideal for the Chattanooga area. The common name comes from how similar the leaves are to culinary rosemary. Both the leaves and the flower are fragrant.

The Cumberland Rosemary thrives in full sun, dry to medium moisture conditions, and is considered only needing medium maintenance, so long as its needs are met. Perhaps the greatest threat to the continuation of this plant in backyards is overwatering.

Habitat Value: Many different insects use the nectar from Cumberland Rosemary as a food source. Thus, many bird species will feed on the insects there. 

This species has no disease or insect problems.

Landscape Value: By Matt Whitaker of WMWA Landscape Architects

Unlike all the plants we have written about so far, I have limited experience with this species. Because low evergreen shrubs are so highly valued by gardeners, and since it is a Cumberland Plateau native with a cultivated selection (“Rocky Top”), I could not pass up its inclusion. Rocky Top only gets to about 6 inches tall and spreads up to 4 feet wide. Its fragrant leaves and flowers make it an ideal groundcover for sunny spots you do not want to mow. The bees and other pollinators will appreciate more natives and less mowing, too. As Charlie notes, good drainage is critical, so do not try it in compact, poorly drained soils. 

Beach Rosemary (Coradina canescens), a cousin, is a coastal plain native I used extensively in Florida. It too tolerates hot, dry environments and is evergreen. Both species are tolerant of high humidity, unlike so many Mediterranean herbs. They also make excellent potted plants for those who have limited space and still want to use natives. Make sure the pot has holes, and skip the saucer.