It’s actually a pretty plant, this beach vitex (Vitex rotundifolia), and it is very good at stabilizing eroding dunes; but folks along the Atlantic coast had no idea how invasive it would become. In the 1990’s the state of South Carolina planted this shrub to help restore dunes lost during hurricanes. It is salt tolerant, produces woody rhizomes (runners) that can extend over 60 feet to trap sand, and has beautiful purple flowers that attract beneficial insects; seems perfect. But over time the residents discovered that it grows aggressively (even extends over driveways) and chokes out many of the native species such as sea rocket and sea oats producing an area of only this plant. (http://www.invasive.org/browse/subinfo.cfm?sub=11609 )
It is now causing problems for sea turtles. As you can tell from some photos in the attached websites, the plant grows over the fore dune blocking access for nesting. It grows so aggressively that during the 60 day incubation time many nests are overgrown entrapping the hatchlings; some have been found entangled within the rhizome mats dead. The problem has become so bad that South Carolina developed a Vitex Task Force to deal with the problem (http://www.beachvitex.org/).
Is this a problem for Florida?
According to the records on EDDmaps.com, beach vitex has dispersed northward to the Chesapeake Bay area and south to Jacksonville. It is found in coastal Alabama and there is one record of the plant in Escambia County. With so few records in Florida it is not currently listed as an invasive species in our state and there is no program set up to control it. However the Sea Grant Extension Agent in Escambia County, Rick O’Connor, was alerted in 2013 that vitex was in Gulf Breeze Florida (Santa Rosa County) and possibly on Santa Rosa Island (Escambia County).
A “Wanted Poster” was developed by O’Connor to post in the coastal communities of Escambia and Santa Rosa counties to see if the plant was more common than the records indicated. At the time of this writing six properties on Santa Rosa Island have confirmed records of vitex and two more will be surveyed soon. The wanted poster program was published in the local newspaper which reached the east coast of Florida. Reports from that coast indicate that it has extended south into Volusia County. Okaloosa/Walton Sea Grant Agent Brooke Saari is posting the wanted poster in those counties to see if the plant has reached their coasts.
Anyone along the coast of the Florida panhandle who feels they may have this plant can contact either Rick O’Connor (850-475-5230; email@example.com) or Brooke Saari (850-689-5850; firstname.lastname@example.org) and we can confirm identification. The plant is not currently listed as invasive in our state and removal is not required. However, based on the experience in the Carolina’s and other invasive species, if you wish to eradicate this plant doing so early is important. It is much less labor intensive and less costly when there are few plants. If you do choose to remove it please contact your local Sea Grant Extension first. We would like to photograph and log the record on EDDmaps. We can also provide methods of successful removal.