During this time of year, some of us are eager to see more green in the rather barren east Texas woods of winter. Sometimes the green we see is not as welcome as we might first believe. While there are many pleasant shades of green out there that come from several types of evergreen trees and vines, there is one shade of green that my eye is particularly trained upon: Japanese Climbing Fern.
The Japanese Climbing Fern is native to Asia and tropical Australia. Like many other invasive species, it was introduced here due to its striking appearance and its ease of cultivation in local gardens. After its introduction in the 1930's, it became a very popular garden addition. Unfortunately, while it may make a particular corner of a garden "pop" with its striking leaves and healthy growth, its escape into our natural habitats can be disastrous. Japanese Climbing Fern can form dense mats, twining and climbing over anything in its way: trees, shrubs, telephone poled, etc. The dense growth shades out native species and reduces diversity in a habitat.
Being a fern, it does not produce a flower and does not reproduce via seed. It thrives and colonizes by rhizomes and spreads rapidly by wind dispersed spores. Those tiny powder-like spores are dispersed not only via the wind but also by any conveyance they can hitch a ride including the mud in your shores, your clothing, your pets and, of course, with free roaming wildlife. Another way it is moved from place to place is in pine straw bales used for mulching your landscape. That is another reason you should insist that any pine straw used to mulch your beds be weed free. You should be leery of what pine straw mulch may bring into your garden as several non-native invasive species can travel the U.S. in these bales.
Another danger these plants may present is found when land managers use prescribed fire to improve habitat health. Prescribed fire is used to reduce fuel sources on the ground and to release nutrients back into the soils to become part of the habitat's food chain. In east and northeast Texas, prescribed fire is most commonly used in the late winter. Unfortunately, Japanese Climbing Fern can act as a ladder fuel, taking fire into the canopy. Fire in the canopy can kill trees that would otherwise have no difficulty with prescribed fire. Infestations of Japanese climbing fern can also intensify wildfire and create optimal conditions to compound the negative effects of the wildfire. These are all great concerns for land managers.
Land mangers are greatly dependent on their neighbors to be plant wise for healthy, safe and successful natural habitats.
All of us need to be good neighbors and good citizens for the natural world that is all about us by being aware of this beautiful but obnoxious plant and other invasive species that can do so much damage to the east Texas woods and their inhabitants.