Lately, I have been greatly concerned with a new invasive exotic plant: aquatic soda apple, aka wetland nightshade, or Solanum tampicense. I had never seen this plant before – in fact, the plant had never been recorded by anyone within Manatee or Sarasota Counties – until I found it on property we own and manage, located at the CR 780/Myakka Road bridge over the Myakka River, just south of Old Miakka. This new invader set off my alarm bells.
Aquatic soda apple, or ASA for short, is a nasty plant. It is somewhat similar to tropical soda apple, its close relative, which you might be familiar with. Like tropical soda apple, ASA is covered in thorns. It also grows tomato-like fruits that are red when ripe; however, ASA fruits are smaller, about the size of a pea, and even more numerous. The small fruits are the perfect size for birds to eat and disperse, which means these plants spread easily.
Different from tropical soda apple, ASA only grows in wetlands (not upland pastures) and is a long-lived, scrambling, vine-like plant, that grows over bushes and up into trees. I have seen ASA with woody trunks that are at least three inches across, growing more than 12 feet into the tops of pop ash trees.
Without tree support, ASA forms dense thickets, worse than the toughest blackberry bramble, up to six feet tall and covering many acres. On our Myakka River property, the largest thicket I found is a little over an acre. If left unchecked, I am afraid it will spread down the entire river, and throughout our region. I heard it has already swallowed large areas of the Peace River, and I have personally seen it along Fisheating Creek. For cattlemen, this is likely to mean the loss of valuable foraging areas along rivers and wetlands; for outdoors people, difficult boat launches and landings; for park managers, a decrease in wildlife habitat, and an ever-expanding management headache.
My top priority on our property is completely eradicating this plant, and my hope is that our neighbors will do the same. If this plant gains a permanent foothold in Sarasota and Manatee counties, it means trouble. I ask land managers to diligently search the wetter parts of their property for this plant, and if they find it, to not only eradicate it, but to talk to their neighbors about checking their property, too.
Spring is the perfect time of year to look for this plant: it’s fruiting in spring and the bright red berries are easy to see; also, the wetlands are dry enough to walk through. If you have any forested wet areas – pop ash, laurel oaks, and bay trees are good indicators – definitely check those areas first.
Regarding control measures, hand pulling works well for smaller plants, but larger plants will require tough herbicide. On our property, straight glyphosate has not been enough – it burned the plants, but they re-sprouted. According to the University of Florida:
Herbicides that have shown the most promise in controlling this species include glyphosate, 2,4-D, and triclopyr. Seeds buried in the soil have been found to maintain their viability for as long as five years. As such, follow-up site scouting of treated areas and additional treatments of newly germinated plants may be necessary (Langeland and Stocker 2001).
On our property, we treated a few acres of the plant with good success. We also walk the wetlands in the spring and hand-pull sprouting recruits. I encourage you to join the effort. Should you have any questions, or want to report a sighting, feel free to email me at lee@conservationfoundation.com.
If you want to learn more about aquatic soda apple, visit UF/IFAS’s Center for Aquatic and Invasive Plants Archive.
