The Enemy: Rocky Mountain beeplant (Cleome serrulata) or spider flower

Strategy: This annual plant is native to the western United States. It usually grows to 3 to 4 feet tall. It produces numerous pink or white flowers with long stamens. The flowers form slender pods (like a bean) that are usually 1 to 2 inches long. Each pod contains many seeds that drop to the ground for the next season. The leaves are slender; if it were not for the reddish stem it would be difficult to distinguish from kochia early in the year. It has a taproot of about 6 to 8 inches.

Attack: This plant is not desirable to livestock due to its unpleasant odor. It likes disturbed sites and does not require much water to survive. It can be found near the railroads, along waterways, right-of-ways, as well as many ornamental and landscape gardens. Once escaping into fields, it becomes a problem. Indians used the plant for food and making pottery paint. The stands of the plant can get thick enough to cause large snowdrifts in the winter if they go untreated near roadways.

Defense: As this plant is an annual, mechanical control either by pulling it (a little moist soil is useful) or by digging them is quite effective. Mowing does not stop the plant from producing seed and only allows it to seed closer to the ground. Early in the season, 2,4-D is effective but once it becomes over 18 inches tall one should combine 2,4-D with Dicamba or another stronger herbicide. Don’t forget to treat our natives with care. Call your local weed professional for proper identification.

To learn more, call Bonneville County Weed Superintendent Jeffrey Pettingill at 208-529-1397 or email weeds@co.bonneville.id.us.