Shorter days may bring a hint of sadness, a reminder that trees will soon be bare and cold weather is on the way. What better way to stave off those "end-of-season-blues" than with bright yellow flowers to greet us in the garden? Gelsemium rankinii, the Swamp Jessamine can do just that. A close relative of the more familiar Carolina Jessamine (Gelsemium sempervirens), Swamp Jessamine is an identical twin except that it produces its cheerful yellow blooms in the Fall as well as the Spring.
Like Carolina Jessamine, Swamp Jessamine is an evergreen vine that will climb just about anything in its path. It will twine around itself to form a three to four foot high mound if grown with no support but it makes a wonderful climber for any lattice work, rock wall or fence post. Swamp Jessamine produces bright, lemon yellow, trumpet-shaped flowers in twos and threes up and down the vine. The flowers are not fragrant but they are a lovely warm yellow which is especially marvelous in the Fall. The vines are covered with flowers in March-April and October-November and a few flowers may open through the winter as well.
Swamp Jessamine has the same cultural requirements as Carolina Jessamine. It likes somewhat acid, moist, organic soils and, in fact, it grows wild in swampy areas of the southeast, hence its name. You don't have to have a swamp in your backyard to grow Swamp Jessamine though because its very adaptable and will survive and flower in many different sites. This vine flowers best and grows the most vigorously in full sun but it also does quite well in shade where the flowers and foliage are just somewhat more sparse. There are no significant disease or insect problems. Propagate Swamp Jessamine by seed or hardwood and semi-hardwood cuttings.
Dr. J. C. Raulston has been evaluating Swamp Jessamine near the deciduous holly collection at The NCSU Arboretum (now the JC Raulston Arboretum) and finds it to be an excellent vine for the landscapes of the Southeast. Look carefully for Swamp Jessamine in the Fall because the only way to tell Swamp Jessamine from Carolina Jessamine is the presence of flowers in the Fall. This can be confusing in a year like this year, however, when our long dry spell has triggered Fall flowering in the Carolina Jessamine as well !
On the way home in the evening, lately, the setting sun has quietened our Summer's mood. If as we turn into the drive, the bright yellow flowers of Swamp Jessamine are dancing up the mailbox to greet us, perhaps we can save a bit of Summer's lighter feeling to bring to the long evenings ahead.