Coastal Invasive Plants - Florida Sea Grant

Photo	Species	Home Range	Problem	Management
Full-Sized Image	Air Potato Dioscorea bulbifera	Tropical Asia	Can grow 8”/day, can grow to the tops of trees and take over native plants	Removing by hand does occur but can cause damage to the tree it is being removed from. There is an approved biological agent (the air potato beetle – Lilioceris cheni – effective, contact your county extension office on how to obtain them, Chemical treatments with dilutions of triclopyr or glyphosate are effective, but retreatments are probably necessary. Contact extension office for recommended concentrations. More information More information
Full-Sized Image	Alligator Weed Alternanthera philoxeroides	South America	Can grow on land or water, develops large mats that expand across the surface of water	Biological controls include: Alligator weed beetle – Agasicles hygrophila Alligator weed thrips (recommended) – Amynothrips andersoni More information More information
Full-Sized Image	Beach Vitex Vitex rotundifolia	Pacific coast of Asia	Grows in open coastal areas, is allelopathic and replace native plants, could impact sea turtle nesting and beach mice ecology	Mechanical removal of the taproot is effective Chemical treatment would include dilutions of glyphosate. More information More information
Full-Sized Image	Brazilian Pepper Schinus terebinthifolius	Argentina, Paraguay Brazil	Very aggressive, shades out native plants reduces habitat for native animals, can tolerate waters greater than 20 ppt.	Mechanical methods can work if you get all roots ¼” in diameter or more, fire will kill tree and seeds but not roots, Foliar application of triclopyr or glyphosate on smaller trees may work, the same products can be used on a stump after cutting, there is a biological control available now. More information More information
Full-Sized Image	Chinese Tallow Triadica sebifera	Asia	It spreads aggressively along “edges”. Will grow in open or shade conditions and even in marine habitats.	Remove small seedlings by hand as the emerge. Larger trees can be cut to a small stump and treated chemically, or a trunk cut can be done and apply chemical this way. The chemical of choice is triclopyr. To obtain the recipe for the herbicide, and when to conduct the cut-spray, contact your county extension office. More information More information
Full-Sized Image	Cogongrass Imperata cylindrica	Southeast Asia	Spreads aggressively, grows well in low nutrient soils, serrated and not preferred by livestock, can enhance prescribed burns to temperatures that can kill trees	In non-crop areas prometon, tebuthiuron, and imazapyr have been effective – however, no vegetation will re-grow for several months. For other areas dilutions of glyphosate, Fluazifop, Fusilade is a selective grass herbicide that provide have had some success, but they are non-select herbicides. An integrated plan using burning, tillage, and chemical treatments seem to work best. Contact your extension office for more details on how to mix these. More information More information
Full-Sized Image	Eurasian Watermilfoil Myriophyllum spicatum	Eurasia or Africa	Develops large mats which blog sunlight and reduces benthic plant growth. It can impact birds and fish.	Mechanical “choppers” can be used but remaining fragments will bring problem back. Some have used this method along with an underwater vacuum. Periodic water drawdowns have helped. Some biocontrol fish have been used and a variety of chemical treatments, including formulations of endothall, diquat, copper, 2,4-D, and fluridone. Certifications are needed, you should contact your county extension office for large problems. More information More information
Full-Sized Image	Giant Salvinia Salvinia molesta	Southeastern Brazil	Forms large mats on the surface of quiet freshwater ponds. Will block sunlight, cause native plant die-off, and lower dissolved oxygen.	Removing by hand with hand nets works with small amounts. Other states have used a beetle (Cyrtobagous salvinae) to control. Large infestations should be reported to FWC. More information More information
Full-Sized Image	Hydrilla Hydrilla verticillata	Southern India	The plant grows towards the surface then spreads vertically forming large mats and blocking sunlight. This decreases native plant diversity. It slows water flow and clogs irrigation and flood-control canals, as well as pumping stations. It can also impact recreational activities in waterways.	Waterway drawdowns can help. Mechanical “choppers” can remove large amounts but leave fragments behind. Chinese grass carp have been effective. Chemical treatments have provided temporary relief. Registered herbicides with copper, diquat, endothall or fluridone have had some success. Many of these require certification, contact your county extension office for more on these herbicides. More information More information
Full-Sized Image	Naupaka Scaevola taccada	East Africa, India, Australia, Polynesia	Displacing native beach plants.	More information More information
Full-Sized Image	Torpedo Grass Panicum repens	Africa Asia	Very aggressive, spread over 70% of Florida’s public waters, management costs are near $2 million annual for flood control, can tolerate water greater than 20 ppt.	Mechanical removal is moderately successful and can – in some cases – increase the problem, Glyphosate is the most effective chemical treatment (there is an aquatic version of this product), best preventive measure is not moving the rhizomes while mowing – even small fragments can start and invasion and waterways are most vulnerable. More information More information
Full-Sized Image	Water Hyacinth Eichhornia crassipes	South America	Clogs waterways making boat travel hard, decreasing dissolved oxygen, lowers biodiversity, costs millions to manage in Florida each year.	Mechanical “choppers” are more effective on this plant than other surface invasive species. There are two weevils that have been somewhat effective but herbivorous fish have not. Registered herbicides do provide temporary relief. Check with your county extension which chemicals and rules on application. More information More information
Full-Sized Image	Wild taro Colocasia esculenta	Asia	Grows in dense patches along waterways. The large leaves can block sunlight and decrease native plant diversity.	They can be removed by hand and shovel, but care should be taken due to the presence of oxalic acid in the leaves, which can be irritating to the skin. Some have had success with 2% glyphosate. More information More information