Lonicera japonica (Japanese honeysuckle)
Lonicera japonica is also commonly known as Japanese honeysuckle. This invasive species is native to East Asia but was brought to Florida in 1875 for agricultural and ornamental purposes (MacDonald et al. 2008). Honeysuckle is a member of the Caprifoliaceae family, which consists of common landscape ornamental plants. In addition to being an attractive ornamental, honeysuckle has been used in places such as highways to control erosion and stabilize banks (MacDonald et al. 2008). However, it grows quickly and can displace native plants, which is why it is considered to be invasive. L. japonica is also very opportunistic and grows well in disturbed areas, fields, roadsides, forest edges and open gaps between other plants (MacDonald et al. 2008). After establishing itself, it can kill native shrubs and vegetation by shading them, or taking away any available water, nutrients and space. L. japonica grows rapidly, has a longer growing season and lacks natural enemies in Florida which enables the vine to thoroughly invade Florida’s natural communities (MacDonald et al. 2008).
Japanese honeysuckle is an evergreen, woody vine that can grow 80-120 feet long. The vine twines and hollows with age. Younger stems are red colored and pubescent and older stems turn brown (MacDonald et al. 2008). Leaves are opposite, ovate shaped, range 1.5 to 3 inches long and may have pubescent petioles. Flowers on Japanese honeysuckle are white to yellow in color, fragrant, and paired in axillary peduncles. Each individual flower is tubular and has a fused corolla with two lips. Flowers are present from April through July and sometimes later in the season. Flower color often helps distinguish Lonicera japonica from other native honeysuckle varieties, especially Lonicera sempervirens (MacDonald et al. 2008). Fruits can also help distinguish between the invasive and native honeysuckles. Native fruits are red or orange in color whereas fruits from Lonicaera japonica are black berries and are produced September through November. Each berry has two or three dark brown or black seeds that are may be up to three millimeters long. Seeds are plentiful after the vine becomes established and dispersal is aided by birds (MacDonald et al. 2008). However, Japanese honeysuckle can also reproduce vegetatively via underground rhizomes or runners aboveground.
Management of Lonicera japonica includes preventative, cultural, mechanical and chemical mechanisms. There are not any current agents of biological control for L. japonica except the limited damage inflicted by grazing deer (MacDonald et al. 2008). Preventative and cultural control methods involve monitoring and preventing plant establishment. This often includes educating those who may potentially plant Japanese honeysuckle and provide alternative native plants such as Campsis radicans (trumpet creeper), Parthenocissus quinquefolia (Virginia creeper), Loniceras empervirens (trumpet honeysuckle) or Asarum canadensis (Wild ginger) (MacDonald et al. 2008). Mechanical control methods may include hand-pulling or hoeing the vine and then removing and destroying all plant material to avoid vegetative growth. Fire can be used to kill seedlings, but often does not kill underground systems. Chemical methods should be timed to be applied after an early frost. This helps to kill the plant at its most susceptible time instead of only killing leaves or foliage (MacDonald et al. 2008).