Non-Native Invasive Plants
Controlling Non-Native Invasive Vegetation
Control efforts of invasive non-natives are ongoing. Fewer Brazilian pepper and Australian pine seedlings are being found each year that our spray crews visit our properties. The removal of these two species from large areas, such as Sanibel Gardens Preserve, Periwinkle/Blue Skies Preserve and the West Sanibel River Preserve, as well as from private individual lots through the City’s Brazilian pepper-removal program has greatly reduced re-infestation.
The West Sanibel River Preserve restoration was completed this summer. One hundred and thirty acres of invasive non-native vegetation were removed and over six miles of ditches were filled. In addition, four ponds were dug on the property and several areas of existing ditch were enhanced to better provide for wildlife.
New invasions of pests continue to pop up and our efforts focus mostly on containment. New patches of torpedo grass, rosary pea, and air potato continue to be discovered and continue to be difficult to eliminate.
Research on Non-Native Control
Controlling Brazilian pepper is pretty straightforward. It responds very favorably to relatively benign chemicals such as Garlon 4, and control can be achieved with minimal nontarget damage to surrounding native species. Many other species, however, are not so easy to keep in check and require the use of very active chemicals to kill the plant, resulting in the loss of surrounding desirable species. Our challenge is find a chemical mix that achieves reasonable control with limited loss to desirable species.
In response to this problem, we have developed chemical trials with two invasive non-natives, the air potato and the snake plant. By trying different mixes of herbicides on plots of these species we can monitor the effectiveness of each to determine the combination that best accomplishes the balance of control and limited impact to desirables.
This information, as it becomes available, is being shared with other land managers on island and off to help in the control of these weeds throughout South Florida.