In a previous column the invasive tuberous sword fern, Nephrolepis cordifolia was reviewed. This week, a nectar producer that is always included in the butterfly garden "must have" list is a plant in the vervain family, porter weed, Stachytarpheta species.
Anxious to increase the Lepidoptera fauna in my rather butterfly scarce community, I purchased several small, cute plants. In those 4-inch square pots they look delicate and reserved. However, within the same year, they had grown into woody stemmed shrubs, almost five feet high and about the same width. The hibiscus shrubs and "Maui" ixora had become engulfed by this nectar producer.
During the second year, porter weed seeds started sprouting and blue porter weed graduated into the nuisance category in my landscape. I hadn't noticed that many butterflies, bees yes, but few butterflies. Had I done my research before the purchase, I would have found that there are at least five species of porter weed and various cultivars that could make it into the retail stores. These include: Stachytarpheta frantzii; the trailing (native), S. jamaicensis; pink snakeweed, S. mutabilis; Stachytarpheta cv. 'Red Compacta'; Stachytarpheta speciosa, coral porter; and Stachytarpheta urticifolia, blue porter.
The last species is the one that grows into the giant that overtakes your landscape beds. The S. jamaicensis or trailing native porter is the more desirable species; it will only get about one to two feet high, but it will spread out about five feet eventually. It will also produce seedlings that will need transplanted or eliminated.
Since both species look similar when they are in those four-inch pots at the store, here are a few identification clues. Even if you read the plant tag at the store, the identification may not be accurate. So remember these tips: trailing porter has leaves that have a "handle" that gives them a racquet ball racquet shape. Blue porter, S. urticifolia, has a waffle-like texture to the leaf and doesn't have the racquet handle shape, also, the serrations are narrower (see picture).
Doug Caldwell is commercial landscape horticulturist with the Collier County Unversity Extension. For more information, contact the University of Florida, Collier County Cooperative Extension Service, Master Gardener Plant Clinic, at 353-2872. For specimen identification, the Extension Plant Clinic at 14700 Immokalee Road is open 9 a.m. to noon and 1 p.m. to 4 p.m. Monday, Wednesday and Friday; call 353-2872. Web site: http://collier.ifas.ufl.edu