The Disadvantages of Honeysuckle

Nonnative Species

• Most nonnative, invasive honeysuckles are bush species, whereas many native species of the genus Lonicera are vining plants. Eurasian bush species that the Forest Service identifies as aggressive are Tatarian (L. tatarica), Morrow's (L. morrowii), Bella or Showy (L. x bella) and Amur (L. maackii). The Forest Service also notes that many other nonnative bush honeysuckles have escaped from home gardens into the wild. These include the Fragrant (L. fragrantissima), Standish's (L. standishii) and European fly (L. xylosteum) species. Honeysuckle spreads not only through cultivation but also by birds that eat the berries and release seeds in their droppings. Japanese honeysuckle (L. japonica) is an invasive vining species.

Native Species

• Trumpet honeysuckle (L. sempervirens), which has bright red, hanging blossoms, is a native plant that the U.S. National Arboretum suggests as an alternative to Japanese honeysuckle. The Arboretum calls invasive plants "landscape thugs" that overrun surrounding native plants. This is because the pests and problems that would control these plants in their native environment are not present in their adopted homes.

  Native bush species that can replace nonnative species include twin-berry (L. involucrata), American fly (L. canadensis), swamp fly (L. oblongifolia), mountain fly (L. villosa) and the honeysuckle relative Northern bush (Diervilla lonicera). Examples of native twining species, in addition to trumpet honeysuckle, are the grape (L. reticulata), Yellow (L. flava),

  hairy (L. hirsuta) and limber (L. dioica) species. The stem centers, or piths, of native honeysuckles are solid white. In contrast, most invasive honeysuckles have hollow stem centers. Native species are shorter and branch less.

Allelopathy

• In a study published in 2004 in "Weed Science," University of Arkansas researchers studied how twining Japanese honeysuckle chemically interferes with certain kinds of pine trees. The study, "Evidence for Allelopathic Interference of Japanese Honeysuckle (Lonicera japonica) to Loblolly and Shortleaf Pine Regeneration," found that the honeysuckle produces five chemicals that may be toxic -- allelopathic -- to pines. They found that Japanese honeysuckle limits the height of pines and causes chlorosis of the trees' needles -- a yellowing indicating a decrease in chlorophyll production.

Controls

• Invasive honeysuckles in home landscaping can be controlled by cutting the plants to ground level and applying herbicides containing glyphosate or triclopyr mixed with a nontoxic bark penetrating oil, according to the U.S. Forest Service. Fortunately, invasive honeysuckles have shallow roots, so it is possible to remove them by hand with the aid of a weed-removing tool. Another manual removal method called "Tug-A-Suckle" involves looping a rope around the base of a honeysuckle plant and having a team of people tug until it is uprooted.