Thursday, March 4, 2010
Sometimes you come upon plants which are astonishingly interwoven in the fabric of human culture. The genus, Verbena, is one of them. The name itself intrigues enough to arouse curiosity. Verbena is sometimes called Vervain.
Verbena is a genus of about 250 annual and perennial species native to the Americas. Two are native to Europe and the Mediterranean region. The name means "sacred foliage", and one of the Old World species, Common Verbena (Verbena officinalis), is most fabled. Common Verbena is now widely naturalized elsewhere. Its potent medicinal properties undoubtedly led to its association with the supernatural.
It's used most commonly in the form of herbal tea to treat nervousness and insomnia. Because of its ability to calm the mind, it has been used to alleviate "writer's block". (I could use some now.) Foliage is pleasingly fragrant. William Faulkner wrote of it in The Odor of Verbena. (I've wondered whether sipping too much verbena tea might have influenced his sentence style.)
Some American Indians used it to "create god within" and induce prophetic dreams. Medieval legend held that the leaves were used as a poultice to staunch the wounds of Christ. Verbena also figures in ancient Egyptian and Greek mythology.
As with most medicinal herbs, verbena has its dangers and should not be used without consulting a physician.
Depending on the species, verbena may be hardy from USDA climate zones 3 through 11. Plant in well-drained soil with exposure to full sun. Recommended pH ranges from 6.5 to 7.8; to err on the side of alkalinity is best.
Growth height varies. Low-profile species are excellent for ground cover, rock gardens, container gardens, hanging baskets and terraces. Taller species are excellent for perennial gardens, cutting and flower-arranging. Verbena attracts butterflies, too.
Prepare the planting bed for verbena by cultivating at least 6" deep, removing all traces of weeds. Compacted soil should be cultivated to 8" deep. Composted manure may be incorporated into the soil. Synthetic fertilizers may be used. To best determine your soil's needs, take a soil sample to your nearby Cooperative Extension office for testing for a small fee.
Container-grown verbena can be planted any time you have a trowel handy, but will require monitoring of soil moisture levels during hot weather to avoid plant stress. Take care not to water too much. Let soil dry between waterings.
Space plants 12" to 24" apart. Keep in mind that my spacing recommendations are approximate. Dig planting holes into the cultivated soil a little less deep than the depth of the growing container. Place the plants into the holes and back-fill. Press soil around the roots. Do not cover the root balls with soil. The tops should be slightly exposed. Add a top-dressing of mulch around the plants, not on top of them, about 2" to 4" deep. Irrigate thoroughly.
Maintenance is minimal. Verbena plants have few pest and disease problems, but they aren't immune. Spider mites can cause problems during dry weather, but the little critters hate water. So overhead irrigation discourages them. Nematodes can attack stems. Removal and destruction of the infected portion is effective. Mildew can infect in areas with poor air circulation during cooler, wetter weather. Sulfur spray is a good treatment. Keep in mind that remedial sprays do not restore damaged tissue; they only stop the progress of the problem. The best preventative is to maintain vigorous plants in a healthy environment.
Ground cover verbena plants benefit from mowing. Yes...mowing. Set your mower at 4" height or greater and trim vigorous plants to maintain a dense appearance. Waiting until they look weak and leggy will not produce good results.
Whether you collect plants for beauty, their history, attractiveness to butterflies, cutting or herbal properties, verbena should be in your garden. With so many species to consider, it's likely that you can find one just right for you. I highly recommend it.
Return to Verbena at goGardenNow.com.