Weed Of The Month: Poverty Sumpweed
 | Author:
Allison Kosto, MSU Broadwater County Extension Agent
MSU Broadwater County Extension Agent |
Weed of the Month: Poverty Sumpweed
Allison Kosto
MSU Broadwater County Extension Agent
Although a native plant, poverty sumpweed is a unique specimen with a foul smell that can be an issue in certain situations. I’ve received a few reports of issues with poverty sumpweed over the years in Broadwater County. It is also sometimes called Povertyweed.
Description & Habitat
Native to western North America, poverty sumpweed is found throughout Montana. It can be found in salt marshes, alkali plains, roadsides, pastures, distributed areas and native rangeland.
Poverty sumpweed is a perennial plant (life cycle of more than two years). It can grow up to two feet tall and is typically found in colonies due to its rhizomatous root system. Its oblong leaves are grayish-green and covered in short bristly hairs. It produces small yellow flowers that can be difficult to see. However, one of the most distinguishing characteristics of poverty sumpweed is that it has a distinctive foul order. People with sensitive skin may react to touching the plant.
Most of the time poverty sumpweed can co-exist without a problem with native or desired forage. However, it tends to be an ‘increaser” which is a plant whose population increases during a disturbance. It also tends to increase under heavy grazing pressure because livestock avoid it and will target more palatable plants. Some research has shown it has toxic qualities when ingested by livestock. Like other weeds, in the right conditions, it can displace native and desired vegetation and decrease forage production and plant diversity.
Management
Little research has been done on poverty sumpweed. Avoiding disturbance or overgrazing is often effective in preventing issues with the plant. Typically, full control is not necessary. Reducing the population in high-density sites can allow the desired species to come back but still leave a few plants to benefit biodiversity.
If control is necessary, it can be difficult due to its intensive root system. Hand pulling is difficult and can cause reactions in some people so make sure to wear gloves. Mowing is generally not effective as the plants will regrow from the roots but may reduce plant vigor if done repeatedly.
Herbicides can be effective. Most commonly used chemicals include 2,4-D, Banvel, Tordon (restricted use) and Weedmaster. A mix of herbicides may provide maximum control. Always read and follow the entire label when applying herbicide. Common chemical names are used for clarity but does not imply endorsement of a product or brand.
For assistance on weed identification and management, contact the MSU Extension Office in Broadwater County at 406-266-9242.
Article Images
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PhotoCredit: Matt Lavin
Image 1 Caption: Poverty Sumpweed
Photo Credits: Matt Lavin
