Smilax Identification & Control: Taming the Thorny Invader

Smilax (green briar, catbrier, deer thorn) is a thorny, waxy-leaved vine with blue-black berries that birds love—but gardeners dread. Its deep, bulbous root crown stores energy, allowing it to resprout endlessly after cutting.

Life Cycle & Why It Persists

From seed, smilax sends up a single shoot and forms an underground tuber. As it matures, a cluster of bulbous roots develops. Most roots stay dormant; killing one shoot only triggers neighbors to sprout.

Control Strategies

Early Detection

Dig out young plants completely before the tuber forms. This is the only sure eradication.

Starvation Method

For established vines, repeatedly clip every sprout as it appears for a full year to exhaust root reserves.

Herbicidal Control

Spray glyphosate on foliage whenever you see it. The waxy leaves hinder absorption, so add a surfactant and apply during active growth.

My neighbor found a smilax root 13′ long!

Bottom Line

Smilax demands persistence. Combine early removal, regular clipping, and targeted herbicide applications to gradually win the battle.