Weed of the Month Archive

The image discusses cutleaf blackberry, an invasive species in Oregon, detailing its characteristics, problems, and management tips.

August 3, 2026

The Dirt | Weed of the Month August 2026 | Cutleaf blackberry (Rubus laciniatus)

Our August Weed of the Month is Cutleaf blackberry (Rubus laciniatus). Cutleaf blackberry is named after its deeply divided ("cut") leaves. Usually…

Info on common tansy: a noxious weed in Oregon, toxic to humans. It has feathery leaves, yellow flowers, and requires management.

July 1, 2026

The Dirt | Weed of the Month July 2026 | Common tansy (Tanacetum vulgare)

Our July Weed of the Month is Common tansy (Tanacetum vulgare). Though it shares "tansy" in the name, it is a different species than the widely known…

Ox-eye daisy (Leucanthemum vulgare) is a noxious weed in Oregon, displacing native plants; management involves digging or herbicides.

June 1, 2026

The Dirt | Weed of the Month June 2026 | Ox-eye daisy (Leucanthemum vulgare)

Our June Weed of the Month is Ox-eye daisy (Leucanthemum vulgare) . Originally from Europe, ox-eye daisy was introduced to North America as a garden…

The image discusses Orange hawkweed, an invasive plant in Oregon, highlighting its identification, issues, and management methods.

May 1, 2026

The Dirt | Weed of the Month May 2026 | Orange hawkweed (Hieracium aurantiacum)

Our May Weed of the Month is Orange hawkweed (Hieracium aurantiacum). Known for its strinking orange flower, orange hawkweed is a perennial…

The image discusses Bristly dogtail (Cynosurus echinatus), an aggressive noxious weed in Oregon, with management tips and identification details.

April 1, 2026

The Dirt | Weed of the Month April 2026 | Bristly dogtail (Cynosurus echinatus)

Our April Weed of the Month is Bristly dogtail (Cynosurus echinatus). One of many invasive annual grasses in Oregon, bristly dogtail is a tufted…

Info about Roundleaf Bittersweet: an invasive vine threatening trees. Management tips include cutting and herbicide use.

March 1, 2026

The Dirt | Weed of the Month March 2026 | Roundleaf bittersweet (Celastrus orbiculatus)

Our March Weed of the Month is Roundleaf bittersweet (Celastrus orbiculatus). Roundleaf bittersweet is a woody vine species that is originally native…

The Yellow Archangel is a problematic, adaptive weed with hairy, variegated leaves; management includes manual removal and herbicides.

February 2, 2026

The Dirt | Weed of the Month February 2026 | Yellow archangel (Lamiastrum galeobdolon)

Our February Weed of the Month is Yellow archangel (Lamiastrum galeobdolon). Yellow archangel is a perennial flower that exhibits lots of versatility…

The image features "Spurge Laurel," an invasive shrub with toxic fruits. It offers management tips for control and highlights its issues.

January 1, 2026

The Dirt | Weed of the Month January 2026 | Spurge laurel (Daphne laureola)

Our January Weed of the Month is Spurge laurel (Daphne laureola).

The image discusses shining geranium (Geranium lucidum), a noxious weed in Oregon, its characteristics, impact, and management methods.

December 1, 2025

The Dirt | Weed of the Month December 2025 | Shining Geranium (Geranium lucidum)

Our December Weed of the Month is Shining geranium (Geranium lucidum). A common weed in roadsides and forest understories, this annual plant is known…

Infographic about garlic mustard, detailing its identification, problems caused, and management for infestations.

November 1, 2025

The Dirt | Weed of the Month November 2025 | Garlic Mustard (Alliaria petiolata)

Our November Weed of the Month is Garlic mustard (Alliaria petiolata). Garlic mustard is a biennial plant, meaning it takes at least two years to…

Reed canary grass: invasive, grows up to 8ft, invades wetlands, reduces biodiversity. Managed by shading, mowing, tarping, herbicides.

October 1, 2025

The Dirt | Weed of the Month October 2025 | Reed canary grass (Phalaris arundinacea)

Our October Weed of the month is Reed canary grass (Phalaris arundinacea). Reed canary grass is common to find along any body of water or where soil…

"False brome is a noxious weed in Oregon. It invades forests. Manage by digging/mowing or herbicide. Benton County CWMA info."

September 2, 2025

The Dirt | Weed of the Month September 2025 | False Brome (Brachypodium sylvaticum)

Our September Weed of the Month is False brome (Brachypodium sylvaticum). False brome is notorious for invading forest understories and edges. It is a…

Tansy Ragwort is a toxic, invasive weed in Oregon, thriving in sunlit areas. Recommended removal: manual digging and herbicides.

August 1, 2025

The Dirt | Weed of the Month August 2025 | Tansy Ragwort (Senecio jacobaea)

Tansy ragwort is an invader of upland prairies, pastures, and anywhere in full sun. The leaves are distinctly crinkly and lobed. This species exhibits…

Infographic on poison hemlock: description, dangers, and management tips, by Benton Soil and Water Conservation District.

July 2, 2025

The Dirt | Weed of the Month July 2025 | Poison Hemlock (Conium maculatum)

Our weed of the month this month is poison hemlock (Conium maculatum). Infamous for being the plant that likely poisoned the Greek philosopher…

"English hawthorn is the Weed of the Month; a noxious shrub in Oregon. Dig up or use herbicide for management. Info by Benton SWCD."

June 2, 2025

The Dirt | Weed of the Month June 2025 | English Hawthorn (Crataegus monogyna)

English hawthorn (Crataegus monogyna) is a shrub or small tree that typically thrives in sunny pastures and partly shaded forest understories. It has…

Poster about oblong spurge (Euphorbia oblongata), a noxious weed needing management, with contact info and images.

May 1, 2025

The Dirt | Weed of the Month May 2025 | Oblong/Eggleaf Spurge (Euphorbia oblongata)

Our weed of the month appears right as its vibrant yellow coloring does. Oblong or eggleaf spurge (Euphorbia oblongata) is a perennial plant that is…

Weed of the Month: Lesser Celandine. Invasive, spreads easily, forms dense mats. Controlled by excavation and herbicides.

April 4, 2025

The Dirt | Weed of the Month April 2025 | Lesser Celandine (Ficaria verna)

Our weed of the month for April is Lesser Celandine (Ficaria verna)!

Infographic on Herb Robert, a noxious weed, describing its features, problems, and management methods.

March 6, 2025

The Dirt | Weed of the Month March 2025 | Herb Robert (Geranium robertianum)

Our weed of the month for March is Herb Robert (Geranium robertianum). This little annual plant goes by a variety of rather fun common names, which…

February 11, 2025

The Dirt | Introducing Weed of the Month! February 2025 | Italian Arum (Arum italicum)

Benton SWCD is excited to introduce our Weed of the Month series. Like other SWCDs, we believe in the importance of highlighting invasive species not…