Green Briar

Green Briar/Greenbriar (Smilax sp.)

Roundleaf Green Briar (Smilax rotundifolia) is the most common of the Smilax species, but other weed names of this species include Bull Briar and Cat Briar.

Many new gardeners are often lured by curiosity to allow a small plant
to grow, not knowing exactly what it is. By catching this one early
a lot of headaches will be saved.

In a few growing seasons this creeping
vine becomes invasive. It has been known
to smother and pull down shrubs then grow upward into mature, well established trees
and bring them down in time to.

In its young stage green briar is more tender. As this vine grows upward, a tendril, or thin winding structure, attaches itself to other vegetation and climbs.

Eventually it becomes a woody vine that
can be rounded or angled with needle-sharp thorns that easily scratch and tear clothes.

Photo: Anita Rust

Weed leaves are heart or spade-shaped and grow 2 - 5 inches in diameter. They are glossy with distinctive parallel veins that run the margin of the leaf. A petiole, or small branch-like stem, attaches the vine to the leaf. Leaves grow off of the vine in an alternating pattern.

The petioles produce the tendrils that wind around other vegetation.

Flowers are small and can be yellowish-green to a yellowish-brown. They bloom in clusters April through August, depending on location. They produce red to dark purple berries which appear in September, but may stay throughout the winter. The seeds that are produced are about 1/4 inch in diameter.

Green briar starts deep in the ground and grows through rhizomes.

This vine grows from one bulb that is so deep in the ground it is rarely possible to get to. This bulb creates rhizome tubers about every 1 -2 feet, which in turn, produces more plants. Although seeds can create new vine weeds, most new growth is created from the tubers.

Hardened roots grow very large and are claw-like in appearance. Roots store water and nutrients quite well, enabling it to grow in any kind of soil with any kind of water supply. These hardened claws also wrap extensively around the roots of wanted trees and plants.

Eradicating this plant is close to impossible and takes a strong commitment. Attempting to hand pull usually results in breaking off the top-growth which the root quickly replaces.

Gardeners who have successfully removed this conglomerate did so by constantly chopping vines down, digging tubers out of the ground or cutting back tubers about an inch or two from the surface. This will be an on-going process.

After cutting back, spray, or paint, a broadleaf weed killer over the freshly cut and exposed tuber. A vine & stump killer or brush killer can be effective, along with crossbow weed killer (and generics) to.

Herbicide options come with no guarantees. The common theme to eradicating this weed is constant weeding management. Your local extension office may also have recommendations.

FYI:

If you can't beat it, join it! Depending on the species, greenbrier roots and petioles are considered delicious, edible weeds similar to the flavor of asparagus.
Herbivorous mammals, like deer, enjoy the foliage and berries, while many butterflies and moths will drink the nectar from the flowers.
The vines are super thorny and painful. Small animals, including pets, have been known to wonder into these vine weeds and get stuck in their briars.
Roundleaf greenbriar has invaded much of the eastern United States from various areas in the great plain states all the way to the coast.

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