Wild buckwheat

Wild buckwheat

The issue: Wild buckwheat

Wild buckwheat (Polygonum convolvulus) is a vining summer annual from Europe. It is commonly found in flower beds, gardens, livestock farms, roadsides, and vegetable and grain crops. Its vining nature allows it to climb anything climbable to maximize photosynthetic opportunities.

Buckwheat is easily confused with field bindweed (morning glory), with its arrowhead-shaped leaves and vining growth habit. Buckwheat leaves are more pointed than bindweed leaves. The seedlings are easily differentiated as the buckwheat cotyledons are long, while morning glory cotyledons are more square-shaped.

The flowers are not showy. A deep, thin taproot helps buckwheat tolerate droughty conditions. The stems have a papery sheath at each node and may be up to 40 inches long.

Wild buckwheat spreads only by seed (12,000 per plant). Seed begin germinating in April and will slow down, but continue, through the summer.

Integrated pest management options:

· Prevention: Keep ditch banks, roadsides, driveways, and walking paths free of seed-producing plants.

· Mechanical: Hand pull plants and destroy any that have flowers on them; tillage is effective.

· Cultural: Maintain healthy, desirable plants.

· Biological: None.

· Chemical: Most effective when plants are less than three inches tall; post-emergent herbicides containing dicamba in home landscape situations, or clopyralid in non-crop areas in mid-spring. Organic burn down products containing pelargonic acid can be effective on young plants. Buckwheat is somewhat tolerant of glyphosate. Be cautious of using herbicides near non-target plants or when temperatures are going to be above 85 F for 72 hours. Be sure the target weed and crop, or landscape situations are listed on the product label. Always read and follow herbicide label directions.

Combine them:

Buckwheat seed remain viable in field conditions for up to five years. Combine different IPM techniques as much as possible for several years. A continual monitoring program is essential.

For more information, contact Ron Patterson, University of Idaho Extension horticulture/agriculture educator in Bonneville County.