Honeysuckle (Lonicera spp.)
Habitats |
Origin and Introduction
| Identification |
Impacts |
Prevention and
Control |
Links
Several species of honeysuckle found in NY are characterized as invasive,
including: Morrow’s honeysuckle (Lonicera
morrowii), Tatarian honeysuckle (Lonicera
tatarica), Amur honeysuckle (Lonicera maackii),
and Japanese honeysuckle (Lonicera japonica). To the non-botanist, native and
invasive non-native honeysuckles appear very similar. One way to distinguish
between native and invasive honeysuckles is by looking at the stems – native
honeysuckles have solid stems while invasive honeysuckles have hollow stems.
All four species are successful invaders of a similar range of
habitats, including: abandoned fields; pastures; early successional, open
canopy, and planted forests; along the edge of woodlots; floodplains; highway,
railway and utility rights-of-way; open disturbed areas; vacant lots; edges of
lawns; and, gardens.
L. japonica can also be found in agricultural
fields. All four grow best in full sun;
L. japonica is the most
shade-tolerant of the four, with
L. tatarica
and L. maackii being semi-shade tolerant.
L. tatarica is native to Central Asia and
Southern Russia and is believed to have been introduced into
North America for ornamental purposes as early as the 1750s.
L.
japonica, – a native of
China,
Japan and
Korea – was introduced for horticultural purposes in 1806
on
Long Island; it was widely distributed as a garden plant through the
early-1900s when it was finally recognized as a weed.
L. maackii, also
native to
China,
Japan and
Korea, was introduced as seeds to arboreta throughout the
U.S. in the late-1800s to determine whether the plant would
grow in
North America. This species of honeysuckle was utilized as a soil
stabilization and wildlife planning until the mid-1980s and is still available
for sale on-line.
L. morrowii, a native of
Japan, was imported to
Massachusetts in the 1860s and was later released as an
ornamental. All four species have escaped cultivation and are easily spread by
birds.
L. morrowii,
L. tatarica, and L. maackii), are
perennial shrubs;
L. japonica is a perennial woody vine (although its
leaves can remain green throughout mild winters). The shrub forms range from 6
to 15 feet in height, while vines can reach 30 feet in length. The egg-shaped
leaves range from 1 to 3 inches in length and are arranged oppositely along
stems. Invasive honeysuckles begin flowering from May to June and bear small
(less than 1 inch long), very fragrant tubular flowers ranging from creamy white
through various shades of pink to crimson.
L. morrowii and L. tatarica produce ¼ inch red berries from mid-summer
through early-fall; L. maackii’s dark-red
berries don’t ripen until late-fall; L. japonica produces
dark-purple or black berries in the fall. Stems of all four are hollow.
All three species can form very dense populations that can
outcompete and suppress the growth of native plant species. These dense stands
suppress the growth of other native species.
L. maackii leafs out very
early in spring, giving it a competitive advantage over native plants.
L.
japonica leaves are semi-evergreen allowing the plant to grow longer into
the winter and giving it a competitive advantage over native vegetation. It
shades out understory growth preventing the success of native understory plants
and tree seedlings. Its vigorous vine growth covers native trees; the weight of
the vine growth can bring down weak trees. By decreasing light availability to
the understory, these invasive honeysuckles can alter habitats by depleting soil
moisture and nutrients. The invasive honeysuckle berries do not contain the
amount of fat and nutrients present in native honeysuckle berries; eating large
amounts of the less nutritious invasive berries rather than native berries can
have negative impacts on migrating.
Because these plants spread rapidly via birds
eating seeds, control should be started in late-summer or early-fall before
seeds are ready to be dispersed. In early stages of invasion, or in cases where
populations are at low levels, hand removal of honeysuckle seedlings or young
plants is a viable option when repeated annually. Systemic herbicides can be
utilized in cases of heavy infestation. Specific state rules should be followed
and the appropriate (low environment impact, legally labeled for control of
these plants) herbicides should be used. For invasive honeysuckles growing in
open habitats, prescribed burning may be an effective control alternative.
Morrow’s honeysuckle (Lonicera
morrowii)
http://nbii-nin.ciesin.columbia.edu/ipane/icat/browse.do?specieId=67
Tatarian honeysuckle (Lonicera
tatarica)
http://nbii-nin.ciesin.columbia.edu/ipane/icat/browse.do?specieId=68
Amur honeysuckle (Lonicera maackii)
http://nbii-nin.ciesin.columbia.edu/ipane/icat/browse.do?specieId=66
Japanese honeysuckle (Lonicera
japonica)
http://nbii-nin.ciesin.columbia.edu/ipane/icat/browse.do?specieId=65