Conradina and xClinadina
11/6/2022 5:08 pm
Conradina sp. and xClinadina 'Desi Arnaz"
Need a tidy shrublike evergreen perennial that can stand up to heat, drought and humidity Want to help preserve a regional native*? Then think about adding a Conradina or a cross of it with another native to the border. Just don't stick it in sodden clay! This is a plant that thrives on neglect.
Conradina sp. are rosemary lookalikes, hence the common name "False Rosemary." Conradina likes it dry, hot and humid and naturally grows in sandy soils. The genus consists of only six or seven species, some of which bloom in the spring and others in the fall. Conradina is in the mint family and crushing the leaves will prove that out by smell. That said, it has no known medicinal or culinary use.
Conradina offers a couple of garden worthy candidates including the pictured cross with Clinopodium (Georgia Savory) above.
The fall bloomers appear to include Conradina canascens, grandiflora, and brevifolia. Why "appear"? Because once these plants are outside of their true native areas they may have different bloom times.
Of these, the most readily available one is Conradina canescens. It is native to the Florida/Alabama panhandle region. Tight, thin, upward grey green leaves distinguish this species. It grows to 1-2' x 1-2'. Woodlanders says this species is highly variable, and that the leaves can be grey or green. C. canescens is not an endangered species. It grew well for me at my prior home near Fernbank Science Center in a sunny, well drained location. I purchased it on advice from George Sanko at what is now Georgia State Perimeter College Native Garden, still a great source of regional natives at their spring and fall sales.
Conradina etonia may be the giant of the fall blooming group which might make it in Georgia, growing 3-4' tall and 2-3' wide. It hails from central Florida and is an endangered species. Such designation means you cannot mail order it out of state, but if you see it at a nursery on your travels one supposes you might bring it back with you in person and help re-populate the species.
Conradina grandiflora (large flowering false rosemary) is endemic to Atlantic coastal Florida. It is listed as threatened in Florida, but not federally endangered. It is an upright species that grows to a similar height as C. etonia, but bears larger inflorescences. It is also the species that bests tolerates a little overhead watering. All that said, it may not be hardy above Zone 9. The literature is scant on non-Florida populations.
Conradina brevifolia is endemic to central Florida and bears short leaves as its latin name suggests. It is quite rare, so details about it seem superfluous other than to say it grows in sand scrub.
The spring bloomers include C. verticillata and C. glabra.
Conradina verticillata (Cumberland Rosemary) is a short growing spreader/sprawler, 6-10" tall, with very skinny leaves. This species hails from sandy creek banks in north central Tennessee and adjacent Kentucky, the only U.S. species not from Florida. You cannot buy this in interstate commerce, so forget out of state mail order. This is the most cold hardy of the bunch, but should do fine here if you could find one in state. C. verticillata is a late spring bloomer. With its demure stature it is perfect for a sunny rock garden spot. Woodlanders sells it in Aiken, SC and Plant Delights in NC offers a cloned cultivar, Conradina verticillata 'Rocky Top', which grows to 6" high.
Conradina glabra (Appalachian false rosemary) is a tall sprawling plant in its native habitat. This Panhandle plant is more of a spring bloomer and grows in scrubby sand. It is on the federally endangered species list for its rarity. It looks like it would not be a particularly attractive garden plant anyway.
According to Plant Delights, Conradina thrives in Florida-like conditions . . . full sun, heat, humidity, and sandy, lean soil. It is also deer and drought resistant. As an added bonus, Conradina roots are allelopathic and inhibit the growth of nearby grasses - making it a good crabgrass fighter.
There is also a hybrid between Conradina and Clinopodium georgianum (Georgia Savory or Georgia Calamint) which Plant Delights calls xClinadina 'Desi Arnaz" and Woodlanders (which discovered it) calls Clinopodium georgianum hybrid 'Desi Arnaz'. This cross, pictured above, has leaves that tend more to green and are a tad wider than true Conradina leaves. It grows to 18" tall with a minty smell. It is fully evergreen in metro Atlanta. It is probably more tolerant of our wet weather than straight Conradina species -- so long as it is in a good draining sunny spot. The inflorescences are definitely Conradina like versus the tubular flowers of Clinopodium. This one has been blooming nonstop from October into November and is a charmer.
Conradinas and Clinopodiums and the cross between them all can be grown from tip cuttings.
* What is a regional native? You might say it is a plant endemic to the state (a political boundary) or an adjacent state, but you'd be hard pressed to say Conradina is from a similar habitat to metro Atlanta or Coastal Savannah or anything in between. Do we fairly call such a plant a native when sold in such areas? Views diverge. What matters to many of us is whether a plant will do well for us in the garden and not be invasive. Will it support native wildlife? The answer to these questions is yes, it will do well in the right growing conditions, and yes, it is attractive to native bees.
The hybrid, xClinadina 'Desi Arnaz' may be the best bet for Georgia gardens not by the coast. It is a lovely, low growing evergreen with charming blooms that takes sun, heat, humidity and drought. Hey Lucy, sounds like a winner to me! - Liane Schleifer