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An area heavily infested with
honeysuckles. In such areas, there may be dozens of such bushes
covering the natural area. The shade they produce is so heavy that
native forbs and grasses are unable to flourish.
There are several species of honeysuckle that cause problems in
Wisconsin natural areas, but there is no reason to classify them
since they are all nonnative and they are all bad. The native honeysuckles
in most of Wisconsin can easily be distinguished from the bad ones
because the natives are mostly woody vines rather than bushes. The
exception is in northwestern Wisconsin where the native fly
honeysuckle is an abundant understory shrub in wet mesic sites.
Bush honeysuckles are upright shrubs ranging from a few feet to
15 feet tall. They form many branches from the base, and the spreading
branches shade other plants. In a honeysuckle "thicket", almost
nothing will be found under the canopy. (After the honeysuckle is
removed, the soil is often bare.) Honeysuckles form fragrant tubular
flowers, followed later by red fruits. Birds are attracted to the
fruits and spread the seeds. Bush honeysuckles have a wide tolerance,
but they prefer partial to full sunlight and are most commonly found
in abandoned fields, forest edges, roadsides, and other open upland
habitats. They are extremely invasive and can easily take over and
dominate a habitat.
Honeysuckle is one of the plants that will invade
a habitat if it is protected from fire. Once honeysuckles have conquered
a habitat, there is no possibility of fire because there is no fuel.
The ground under a honeysuckle patch is often completely bare. In
order to reintroduce fire, it is essential first to eliminate the
honeysuckles and then reseed with native plants, preferably seed
mixtures containing grasses such as Indian grass or bluestem that
will carry a fire.
Close up of honeysuckle flowers.
In southern Wisconsin, flowering occurs in late April or early May
Both mechanical and chemical methods must be used together on honeysuckle.
The most assured method is to cut all the stems of a plant and treat
each cut stump with a 20% solution of glyphosate. The concentration
given here is percent of the active ingredient. Concentrated glyphosate,
such as Roundup Ultra, is around 40% out of the bottle, so that
a 20% solution can be made by mixing equal parts of glyphosate and
water. (Some sources recommend lower concentrations of glyphosate,
but with the higher concentration resprouts are less likely to occur.)
Honeysuckle can be cut with either a brush cutter or a hand lopper.
The hand lopper works well and is suitable in volunteer work parties,
because each volunteer can participate in cutting. If a stem is too
large to cut with a lopper, a handsaw can be used. With a brush cutter,
it is important that the cutting blade be sharp. With a dull blade,
the cut stems are often shredded and splintered, making them harder
to treat with herbicide. For the largest stems, a chain saw may be
necessary. No matter which cutting method is used, it is essential
that the stumps be cut sharp and straight across, so that the cut
stumps can be treated with herbicide (as described below).
The tools of the honeysuckle trade. Hand loppers,
a spray bottle containing 20% glyphosate and a red dye, and persistence.
Here is a procedure guaranteed to work:
With practice, this procedure works quite well and the honeysuckle
plants should not resprout. Note that with this procedure, the herbicide
is confined only to the cut stumps and is not spread around the
Honeysuckle cut stumps treated
with glyphosate. The red dye (blue will also work) ensures
that all stumps have been treated. Count the stumps as they
are cut, and again as they are treated.
Research has shown that in southern Wisconsin honeysuckle can be
cut at any time of the year. Winter is an excellent time to cut,
and glyphosate works quite well then.
This honeysuckle bush was cut
and the cut stumps were not treated with herbicide. Resprouting
has resulted in a large number of stems.
Honeysuckle is very persistent, and will resprout readily if not
treated with herbicide.
Please note: There is no point in cutting honeysuckles if they
are not going to be treated with herbicide.
We do not recommend hand pulling, as some authorities do, because
it disturbs the soil and opens it up for establishment of weeds.
After the honeysuckles have been taken care of, the area should
be reseeded with native species. This is especially important because
when the honeysuckles are removed a "hole" has been created, into
which weeds will readily move. In fact, if the honeysuckles were
almost solid, it might be preferable not to remove them all at once,
but to gradually cut them back, seeding with native species as you
go. It may take several years to eliminate the honeysuckles in this
way, but this may be preferable to creating a habitat full of weeds.
Once honeysuckles have been eliminated from a natural habitat,
they can usually be kept out by controlled burning. Remember, there
will be a seed bank, so that small honeysuckles will appear next
year. If the habitat is not burned, these small honeysuckles will
grow big and you will have the same problem again. Once established,
native grasses will carry a fire and help keep the honeysuckle seedings
Please note: Eradication of honeysuckle should not begin until
an approved burn plan has been developed. For the first few
years after removal of honeysuckle from an area, annual burning
is recommended, so that the new seedlings are destroyed.
To download a printable Adobe Acrobat (pdf) version - click here.
See also Wisconsin DNR site.
Plant List (pdf)
Interactive Plant List
A Role for Native Weeds
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