By Les Harrison
Wakulla County Extension Director
Hints of spring are everywhere in Wakulla County. Despite a few potentially frosty morning in the next few weeks, the evidence is overwhelming of the warmer weather soon to come.
The buds on many trees, shrubs and other plants are readying with a burst of growth and color. The leaf litter’s earth tones are harboring the pleasant surprises of growing season close at hand, but also some arrivals will be disagreeable.
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 millions of dollars every year to control in the southeastern U.S.
The air potato is a member of the yam family. This hearty vine is a native of Asia and sub-Saharan Africa where yams are commonly cultivated for their edible roots.
These tubers have long been an important dietary staple for the region’s residents.
This plant was brought to the Americas from Africa during early 19th century and introduced to Florida around 1905 for its ornamental potential.
It is currently found throughout the state from Escambia County in the Panhandle to the Florida Keys.
It has also escaped into the wild and established itself in Mississippi, Louisiana, Texas, Hawaii and Puerto Rico.
Air potatoes are easy to spot. The unique green leaf is heart shaped and sharply tapers to a point at the tip. It has twining herbaceous round vines with stems growing up to 60 feet in length.
Unlike edible yams, the tan-colored 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 the tops of 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.
While the stems and foliage die 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 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’ lists as a problem plant and is illegal to propagate and relocate.
Air potato can be controlled by removing every bulb before it sprouts in the coming weeks.
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.
Then, hopefully, spring’s return will resurrect enjoyment of the native plants, not invaders attempting conquest.