By Mark Czarnota
University of Georgia
Volume XXVIII
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Weedy vines in the landscape can cause mayhem for even the
most proficient
gardeners. Among the worst are greenbrier, honeysuckle,
Virginia creeper and
poison ivy.
The culprits
Greenbrier (Smilax species) is native to North
America. It’s related
to day lilies, lilies and yucca, but all Smilax species are
vines. They all
have extensive underground rhizome tuber systems. Most have
thorns. The plants
can be male or female, and females bear black, blue or red
fruits.
Honeysuckle (Lonicera japonica) is a semievergreen
vine. Of the 16 to
20 species of Lonicera, only a handful are climbing vines.
Most of the vines
have woody rhizomes that can be hard to remove. Honeysuckle,
has two types of
leaves and flowers that produce a wonderful nectar.
Virginia creeper (Parthenocissus quinquefolia) is
native and related
to grapes and porcelain vine. It grows much like grape vines
and can form mass
thickets. When not being weedy, Virginia creeper is known for
its outstanding
fall color.
Poison ivy (Toxicodendron radicans) is a clinging,
twining vine. Most
people recognize it by the old adage, “Leaves in three, leave
it be!” It can
produce an extensive, hard-to-remove, underground rhizome
system. The plant
produces an alcohol-like substance that can cause severe skin
reactions, so
beware when trying to remove it by hand.
How’d they get into my shrubs?
Many other woody vines can be weedy. But these four all have
fleshy fruit that
birds relish. When the fruits ripen, birds eat them and can
deposit the seeds
in the crown of ornamental shrubs.
Seeds that pass through the bird and germinate can get a good
foothold before
showing up. Once they’re visibly growing inside prized shrubs,
most gardeners
clip out the intruder. Occasionally, this works. More often,
though, the vine
will keep coming back like an irritating in-law.
Eliminating vines can be difficult
If pruning fails, you can always try to physically remove the
plant. This often
won’t be an option, though, because the vine will have emerged
from the center
of the shrub. Plants like smilax have an extensive underground
rhizome tuber
system, too. This makes digging the plant out impossible in
such close quarters.
With these options exhausted, you can either try to enjoy
your newfound resident
or consider using herbicides. Many herbicides are labeled for
the control of
these vines. Most, however, can’t be applied near desirable
ornamentals.
One herbicide, glyphosate (sold under the
name “Roundup,” “Razor” and others),
can be used in many ways. Here are two of the best.
- When the plant is fully leafed out (late April to late
October), unravel
the vine from the desirable plant. If you’re doing this with
poison ivy, wear
gloves and a long-sleeve shirt. Remove as little of the vine
as possible,
and be careful not to break any stems. Lay the vine on some
bare ground or
on a piece of plastic. Spray or sponge-apply a 5-percent
solution of glyphosate.
Make sure the product you use to make the 5-percent spray
solution contains
41 percent or greater active-ingredient glyphosate. Be
careful not to spray
or let the solution drift onto desirable foliage or bark.
Allow the vine to
sit for 48 hours. Then cut the stem back to the ground. If
the treated vine
starts to regrow, spray or wipe a 5-percent glyphosate
solution to the sprouts
when they’re 6 to 8 inches tall. - If the weedy vine can’t be unraveled from the desirable
shrub, cut it as
close to the ground as you can and immediately paint
concentrated glyphosate
on the cut stem. (Make sure it’s 41-percent or more
glyphosate.) If the plant
regrows, sponge on or spray a 5-percent glyphosate solution
when the sprouts
are 6 to 8 inches tall.
