War on Weeds: Jerusalem oak


Dale A. Zimmerman Herbarium

This weed may invade your land. Be ready to oppose it.

The Enemy: Jerusalem oak (Dysphania botrys or Chenopodium botrys)

Strategy: This annual herb that has invaded the Northeastern U.S. was recently found as a weed in tje Lemhi County area. It is generally considered a herb. It grows to a height of 2 feet and has hairy, deeply lobed leaves that occur in opposite locations on the stem. The leaves appear to have numerous glands upon them. It produces very small pink to purple flowers that occur in clusters at the margins of the leaves and the stem. The flowers are as well very pubescent (hairy.)

Attack: This plant prefers open sunlight such of which can be found in disturbed soils along roads, empty lots and some landscapes. Although the plant was brought in as a herb for medicinal uses as well as for cooking, it can become toxic if too much is consumed. It should be cooked and not eaten raw. Once the plant is established, it consumes an area as it produces hundreds of seeds and livestock will choose to stay away from it.

Defense: If you didn’t plant it, kill it and ask what it was — one of my favorite sayings. In some cases where the desired plant escapes, one is forced to control the invasiveness of the plant. Since this plant is an annual, it is quite effective to pull or dig up the invader and deposit into the trash bin. Since this plant is in the Amaranthacae family, one should could use 2,4-D in the early spring and move to a combination of 2,4-D and Dicamba (Banvel, Vanquish, Clarity, etc.) Once you see the plant starting to flower, spraying will be less effective and you should consider mowing to reduce the spread of the weed to adjacent areas.

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