Weed Gallery Fact Sheet

This page contains a listing of the Noxious and Secondary class weeds within Nobles County

Prohibited Noxious Class Weeds

The plants listed in this part are prohibited noxious weeds because they, are injurious to public health, the environment public roads, crops, livestock, and other property. Prohibited noxious weeds must be controlled or eradicated as required in Minnesota statutes.

Canada Thistle

Origin: Eurasia
Life Span: Perennial
Height: 1–4 ft.
Flowers: July–August

Distinguishing Marks: Forms colonies, leaf surface smooth with prickly margins. Flowers at the ends of the stem.

Wanted For: Invading almost every place in Minnesota. Can grow in wet or dry soil, especially on roadsides and pastures.

Bull Thistle

Origin: Eurasia
Life Span: Biennial
Height: 2–5 ft.
Flowers: All summer until frost

Distinguishing Marks: Prickly throughout especially on leaves and margins. Also look for hairs on the leaves, especially on the bottom.

Wanted For: Highly invasive in all soils, especially on roadsides and pastures.

Origin: Europe
Life Span: Perennial
Height: 1–4 ft.
Flowers: June until frost

Distinguishing Marks: Look for a prickly stem on this plant. The leaves are also very prickly. The flower heads are found singly or as clusters at the tip of the stem. No plume on the seeds.

Wanted For: Invading roadsides, pastures and waste places in Minnesota.

Musk Thistle

Origin: Eurasia
Life Span: Biennial
Height: 3–6 ft.
Flowers: June until frost

Distinguishing Marks: The flower bracts are purple, large and curve downward. The leaves are prickly with a wavy margin.

Wanted For: Invading roadsides, pastures and waste places in Minnesota.

Perennial Sowthistle

Origin: Eurasia
Life Span: Perennial
Height: 2–4 ft.
Flowers: June–October

Distinguishing Marks: Yellow flowers at the ends of slender stems. Flowers look like dandelion flowers. Leaves near the ground with prickly margins.

Wanted For: Invading anywhere a seed can germinate. Will out-compete almost anything in its path.

Purple Loosestrife

Origin: Eurasia
Life Span: Perennial
Height: up to 8 ft.
Flowers: July–August

Distinguishing Marks: Tight clusters of purple flowers, sharply edged stem and leaves opposite and whorled at each node distinguish this invader.

Wanted For: Invading almost any shallow water in the state. Can out compete almost any other plants.

Warning: Do not spray areas posted for biological control.

Field Bindweed

Origin: Europe
Life Span: Perennial
Height: Vine up to 2 ft.
Flowers: May–September

Distinguishing Marks: A vine up to 2 ft. long with large trumpet shaped white flowers and arrowhead shaped leaves mark this plant.

Wanted For: Invading established plant communities as well as form fields and roadsides.

Hemp

Origin: Eurasia
Life Span: Annual
Height: 3 to 9 ft.
Flowers: August until frost

Distinguishing Marks: Easily identified by leaf. Leaf is compound with 7 -9 leaflets which are toothed and have prominent veins.

Wanted For: Can be an intoxicant and is aggressive.

Leafy Spurge

Origin: Eurasia
Life Span: Perennial
Height: 1.5 to 3 ft.
Flowers: Late spring/early summer and again in fall

Distinguishing Marks: Look for leaves crowded on the stems with a whitish color. Look for a milky juice when the leaves or stems are broken.

Wanted For: Being a highly invasive weed, crowding out almost anything in its way, and being almost impossible to kill.

Warning: Do not spray areas posted for biological control.

Poison Ivy

Origin: Native
Life Span: Perennial
Height: 6–12 inches (typical)
Flowers: May–July (looking for flowers is discouraged)

Distinguishing Marks: Look for leaves crowded on the stems with a whitish color. Look for a milky juice when the leaves or stems are broken.

Wanted For: Causing sometimes severe rash in susceptible people. Poison Ivy is also an invasive weed.

Mustard, Garlic

Origin: Europe
Life Span: Biennial Height: 1–4 ft.
Flowers: May

Distinguishing Marks: First year plants consist of a cluster of 3 or 4 round, scallop edged leaves rising 2 to 4 inches in a rosette. Second-year plants generally produce one or two flowering stems with numerous white flowers that have four separate petals.

Wanted For: This plant is a major threat to the survival of Minnesota's woodland herbaceous flora and the wildlife that depend on it.

Secondary Class Weeds

Cocklebur

Origin: Native
Life Span: Annual
Height: 3–4 ft.
Flowers: July–September

Distinguishing Marks: Look for rough hairy stem, often spotted. Leaves are alternate triangular shaped, sometimes toothed or lobed. Woody stout taproot.

Wanted For: Invading open fields, gardens, pastures and waste areas, especially where receding water has exposed previously submerged land.

Warning: Seedlings in cotyledon stage are poisons to livestock.

Velvetleaf

Origin: India
Life Span: Annual
Height: 2–4 ft.
Flowers: July–October

Distinguishing Marks: Look for alternate heart shaped leaves covered with soft velvety pubescence. Seed is found in cup shaped pod about an inch in diameter with a ring of prickles about the upper edge. Also known as Buttonweed.

Wanted For: Invasion of row crops, especially later in the season after cultivation.

Warning: May cause an allergic skin reaction in susceptible individuals.