By Les Harrison
Wakulla County Extension Director
The leaf litter and pine straw so common to Wakulla County lawns and landscapes this time of year obscures a variety of items from view. The mulch in the making is a resource which literally falls from the sky, or at least that direction.
In addition to the benefits, there are some drawbacks. This plant debris can hide some insidious invasive plants and give them time to become established.
Unfortunately, this is reality when it comes to Dioscorea bulbifera, better known as air potato. This pest is a difficult to control exotic plant which has caused severe damage to sections of the native environment and costs taxpayers millions of dollars a year to control in the southeastern U.S.
The Air potato is a member of the yam family. This hearty perennial vine is a native of Asia and sub-Saharan Africa where yams are commonly cultivated for their edible roots. These tasty tubers have long been an important dietary staple.
This member of the yam family was brought to the Americas from Africa during early 19th century and introduced to Florida around 1905. It is currently found throughout the state from Escambia County in the Panhandle to the Florida Keys. It is also established in Mississippi, Louisiana, Texas, Hawaii and Puerto Rico.
Air potato is easy to recognize in the wild. The green leaf is heart shaped and it sharply tapers to a point at the tip. It has twining herbaceous vines with stems growing up to 60 feet in length. The vines are round and tan colored tubers similar to a potato hang from the vine.
Unlike edible yams, the tubers on air potatoes are produced on the vine. They may be as large as small Irish potatoes or smaller than the circumference of a dime.
Air potato tubers are generally bitter and may even be toxic to mammals. It has little or no value to the native wildlife as a food or shelter source.
It grows aggressively in the warm Florida climate covering eight inches per day. It will quickly climb to tree tops trees.
Once in the tree’s crown a mat is formed which weighs down and smothers the tree. Air potatoes will cover and suffocate everything in its path as it colonizes an area.
Even though the stems and foliage of the vines are dying back as winter approaches in Wakulla County, the plant is still a problem because of its tubers or bulbs. Each time the vine drops a “potato”, another plant is likely to grow from it.
Once the potatoes drop and are buried under soil or covered with leaf litter, they become difficult to spot and remove. Even air potatoes the size of a pea will start a new plant.
With air potato having no natural enemies in Florida and the capability to displace native species, it has been identified as one of Florida’s most invasive plant species. It is on numerous agencies’ list as a problem plant and is illegal to propagate and relocate.
Air potato can be controlled by picking up every bulb hitting the ground before it sprouts. Once the bulbs are removed, the vine can be treated with a broad-leaf herbicide. Typically at least one follow up collection of bulbs will be necessary.
It is not nearly as fun as searching for Easter Eggs, but it is good practice.
To learn more about identification and control of Air Potato in Wakulla County, contact your UF/IFAS Wakulla Extension Office at 850-926-3931 or https://blogs.ifas.ufl.edu/wakullaco/