UF/IFAS Okeechobee County Extension Service

458 Highway 98 North

Okeechobee, FL 34972-2578

Phone: (863) 763-6469

E- mail: dfculbert@ifas.ufl.edu

March 3, 2004

Feature Article - for release the week of March 7, 2004

Dan Culbert - Extension Horticulture Agent

It’s potato-picking time!  No, it’s not time to harvest the "roots" of your garden labors, but it is time to prevent the spread of one of our most difficult weed problems. Air Potatoes are a killer vine that can even out-compete kudzu. With spring’s arrival, it is ready to begin to grow over your favorite landscape plants and take over our roadsides and natural areas.

If you have had problems with this invader, take a careful look on ditch banks and under trees and shrubs. You may find many dark brownish "potatoes". Pick them up and dispose of them in the trash, or add them to a burn pile. Otherwise, in a few weeks, you won’t see them - because they will have sprouted and covered over the ground and the trees in your Florida Yard.

Air potatoes are relatives of the yam family. Their attractive heart-shaped leaves can measure 8 inches across. Discorea bulbifera, as it is known to botanists, rarely produces flowers, but instead produces fleshy bumps on the stems where it stores food. They were brought to the US early in the 1900's for possible food or medicinal use, but proved worthless for these purposes.

Air potato vines have been spread by unsuspecting gardeners who like their shiny slick appearance, rapid growth, and pest-free status. Unfortunately, these features also mean that it can rapidly get out of hand.

At the end of the growing season the vines die, and frost will make it seem like it has disappeared. But, these fleshy inedible tubers lie in wait on the ground, or are buried in the soil surface, and will soon resume their growth. The vines are capable of covering trees to a height of 70 feet or more, and with that kind of covering, trees will not survive this darkened blanket.

Removal of the tubers works to reduce the infestations, but may be backbreaking. Why not have a contest among your family or neighborhood to see who can collect the most. The city of Gainesville has an annual Air Potato roundup, and in 2002 picked up 8 tons of "air-spuds" with 800 volunteers; they gave out awards and provided entertainment to encourage this removal effort.

Chemical control of air potatoes is challenging, and involves re-treatment of the vines with non-selective weed killers like glyphosate (Roundup ™ ) or triclopyr (Garlon™ ). The problem with these products is they will kill whatever they touch, including the plant you are trying to protect. Follow the label carefully to be sure any weed killer used will not hurt the environment or desirable landscape plants.

University of Florida has sent Weed Scientist Dr. Bill Overholt to the native African range of this vine, Ghana and Uganda. There are hopes that he will find some natural pests that can put the pressure on the air potato. Extensive screening of potential biological control agents will be conducted at the UF Agricultural Research station in Fort Pierce, and in five years may result in some relief from this invasive weed.

So, in the meantime, pick a peck of air potatoes, put them in the trash for land filling, or burn them if permitted. Don’t dump them somewhere else where the will spread, and don’t add them to the yard trash pickup pile. Follow up with careful directed applications of brush killers to hold back the resprouting vines, and you will be able to see the forest and the trees this summer.

We have bulletins on Air potatoes and their management here at our office and on-line at our website, http://okeechobee.ifas.ufl.edu . Master Gardeners can answer your questions about your Florida Yard - call or visit them on Tuesday afternoons here at our office. If you need additional information on air potatoes, stop by our office at 458 Hwy 98 North. Our phone number is (863) 763-6469, and you can email us at okeechobee@ifas.ufl.edu .

Trade names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin. Florida Cooperative Extension Service / IFAS /University of Florida.  Larry A. Arrington, Acting Dean.

References

Air Potato Dioscorea bulbifera. Gainesville: UF/IFAS Center for Aquatic & Invasive Plants, 2001. http://aquat1.ifas.ufl.edu/diobul.html

DelValle, Terry. "GARDEN HELP: Attractive air potato plant is on Noxious Weed List." Jacksonville: Florida Times Union, 9/27/03. http://duval.ifas.ufl.edu/agriculture/hohorticulture/gardenqa/092703a.html

Langeland, Ken. Natural Area Weeds: Air Potato (Dioscorea bulbifera) Gainesville: UF/IFAS, SS AGR 164., May 2001. http://edis.ifas.ufl.edu/AG112

Overholt, Bill et.al. Air Potato in Florida Gainesville: UF/IFAS Extension Service ENY-698., [undated - 2003] http://kgioeli.ifas.ufl.edu/airpotato.pdf .

Overholt, Bill "UF/IFAS Connection with Ghana may help control the air potato." Gainesville: UF/IFAS International Focus Newsletter, 14:6, October 2003. http://international.ifas.ufl.edu/focusweb/focusoct03002.htm

Last update: 03/04/2004 .  This page is maintained by Dan Culbert