The Top 5 Most Invasive Plants Found in the Nature Coast
Air Potato, Dioscorea bulbifera
A native to tropical Asia, air potato, Dioscorea bulbifera, was introduced to Florida in 1905. Due to its ability to displace native species and disrupt natural processes such as fire and water flow, air potato has been listed as one of Florida's most invasive plant species since 1993, and was placed on the Florida Noxious Weed List by the Florida Department of Agriculture and Consumer Services in 1999.
Air potato can grow extremely quickly, roughly 8 inches per day. It typically climbs to the tops of trees and has a tendency to take over native plants. New plants develop from bulbils that form on the plant, and these bulbils serve as a means of dispersal. The aerial stems of air potato die back in winter, but resprouting occurs from bulbils and underground tubers. The primary means of spread and reproduction are via bulbils. The smallest bulbils make control of air potato difficult due to their ability to sprout at a very small stage.
Japanese Climbing Fern, Lygodium japonicum
- Lygodium japonicum, or Japanese Climbing Fern (JCF), is an adventive species that was introduced into Florida as an ornamental plant in the 1930's.
- Japanese climbing fern is a perennial vine-type fern, reaching up to 90 feet in length. Its leaves are lacy and finely divided, arranged opposite on the vine.
- This invasive plant often infests trees and shrubs forming dense mats of vegetation.
- Vines formed from branches arise from underground rhizomes, which are slender, black and wiry. Fertile fronds are usually smaller segments with fingerlike projections around the margins. These bear sporangia (spore producing structures) in double rows under the margins. These are very tiny and easily dispersed by wind.
- Japanese climbing fern can grow in sun or shade, damp, disturbed or undisturbed areas. It can grow so dense that it forms a living 'wall', leading to the elimination of seedlings and other native vegetation. Japanese climbing fern was added to the Florida Noxious Weed List in 1999. It is also a major problem in pine plantations, causing contamination and harvesting problems for the pine straw industry.
- Small infestations can be carefully hand-pulled or treated with a 3-4% solution of a herbicide containing the active ingredient glyphosate.
Brazilian Pepper, Schinus terebinthifolius
- Schinus terebinthifolius or Brazilian Pepper is a plant in the sumac family that is native to Brazil and Paraguay.
- Brazilian pepper is a tree that can grow to nearly 40' tall and is a rapid resprouter, often assuming the form of a shrub or bush, especially if previously cut or damaged.
- This plant favors subtropical and tropical climates and flourishes in the coastal areas from Levy County on the west and as far as St. Johns County on the east side of Florida. It will occupy interior areas of Florida from Orange County south.
- This plant blooms heavily in the fall and fruits heavily with a small round drupe or berry in the spring, but plants can reproduce year round. It can reach maturity from seed in as little as four years.
- This plant obscures views, crowds out other vegetation by overtopping or preventing germination and generally will provide inferior wildlife habitat and a decreased diversity of trees and plants over time.
- Small plants (less than 8") can typically be hand pulled but as they can be irritating gloves should be worn. Larger trees are typically treated with a 15-20% solution of any herbicide with the active ingredient triclopyr ester in a basal oil mix applied to the bark at the base of the tree.
Chinese Tallow, Sapium sebiferum
- Sapium sebiferum or Chinese Tallow is a tree native to Southeast Asia. Its major historical use has been as an ornamental (yard) tree but there has been some interest in this tree as a source for oils or other energy products.
- This tree was legal to sell until 1998 and was extensively used as a landscape tree in coastal and interior developments including city median projects.
- Chinese tallow is an aggressive resprouter if cut and can grow to over 40 feet. The leaves have a characteristic heart or aspen shape at the bottom and are alternate and entire. There is a fall color (red) to the leaves before it loses the leaves for the season.
- This plant has wide distribution over the local area, but favors areas adjacent to wetlands, displacing willow, wax myrtle, sweetgum and maple trees.
- This plant has fruit/seeds that resemble popcorn from a distance, earning it the nickname 'popcorn tree'. Its sap is white and milky.
- This plant obscures views, alters hydrology, crowds out native vegetation by overtopping or outcompeting and generally will provide inferior wildlife habitat and a decreased diversity of trees and plants in a natural area over time.
- Small plants (less than 8") can typically be hand pulled but larger trees typically need chemical treatment. Larger trees are typically treated with a 15-20% solution of any herbicide with the active ingredient triclopyr ester in a basal oil mix applied to the bark at the base of the tree. Care should be exercised to obey the label requirements especially where this tree grows in wet areas. In these spots, a different chemical such as imazamox can be used.
Cogongrass, Imperata cylindrica
- Cogongrass is an aggressive, rhizomatous, perennial grass that is native to Southeast Asia. It has become established in the southeastern United States within the last fifty years and was first introduced into Florida in the 1930s and 1940s as potential forage and for soil stabilization purposes.
- The leaves are light green, originating directly from ground level and range from one to four feet in length. Each leaf is 1/2 to 3/4 of an inch wide with a prominent, off-center, white mid-rib. The leaf margins are finely serrated; contributing to the undesirable forage qualities of this grass.
- It has been shown that an integrated approach that combines burning, tillage (mechanical disturbance) and chemical applications provide the best solution for cogon grass management. For best results, herbicide applications should be made in the late Summer/early Fall. The herbicides glyphosate (Roundup, others) at a 2% rate and imazapyr (Arsenal, Chopper) at a 0.5-1.0% rate, have been shown to provide the best control.