CORVALLIS, Ore. — With trumpet-shaped flowers and thin, twining stems, bindweed is one of the most frustrating weeds for home gardeners.
"This invasive perennial is one of the most noxious weeds in the world."
“This invasive perennial is one of the most noxious weeds in the world,” said Marcelo Moretti, Oregon State University Extension weed specialist.
Two species are common in Oregon: field bindweed (Convolvulus arvensis) and hedge bindweed (Convolvulus sepium). Both belong to the morning glory family but are often mistaken for wild buckwheat or ornamental morning glory, which are non-invasive annuals.
Bindweed’s arrow-shaped leaves grow opposite each other on the stem. Juvenile stems exude a milky sap when broken. Flowers, ranging from white to pink, bloom throughout the year.
Native to the Mediterranean regions of Europe and Asia, bindweed has spread worldwide. It was first recorded in the United States in 1739 and by 1850 was documented in California.
Why it’s a problem
Bindweed sinks roots as deep as 9 feet and spreads aggressively both by seed and underground rhizomes. Seeds can remain viable in soil for years. Most horizontal roots grow in the top 2 feet, but fragments as small as 2 inches can regenerate.
In gardens, bindweed smothers plants as it climbs and wraps around stems and structures. In crops such as wheat, potatoes and legumes, it robs yield. In blueberries, it weaves into bushes, complicating harvest.
“Bindweed tolerates poor soils but seldom grows in wet or waterlogged areas,” Moretti said.
Strategies for control
Managing bindweed requires persistence over multiple years. Mowing is ineffective, but two main approaches offer results:
- Digging and pulling: Repeated removal every 2–3 weeks during the growing season eventually depletes the root system. Use a garden fork or deep cultivation tool to remove as much root as possible. Be prepared for regrowth in about two weeks.
- Herbicides: Glyphosate products, such as Roundup, can be effective if applied carefully to avoid drift. The best time for treatment is at flowering, when the plant is actively moving nutrients to roots. Multiple applications are often needed because of the plant’s extensive root system.
The bottom line
Control of bindweed isn’t quick, but consistent effort pays off. “Persistence and dedication are required,” Moretti said. “Repetitive digging and pulling will ultimately deplete the root system and provide control.”
Previously titled Controlling perennial bindweed takes persistence
