August

Purple to Pink Flowers

Canada Thistle

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  • A perennial that spreads by roots and seeds
  • Grows 1 to 4 feet tall
  • Has clusters of small, white to purple flowers at the end of the stems
  • Leaves are very spiny - it hurts to touch this weed!
  • Grows in moist and disturbed sites
  • This invasive weed is very aggressive and difficult to control
  • Pulling and burning do not control this weed, as they favor root resprouting
  • Chemical controls are needed

Musk Thistle

Purple Loosestrife

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  • A perennial that spreads by roots and seeds
  • Grows up to six to eight feet tall
  • Produces a spike of showy purple flowers in August
  • Stems have square edges
  • In the past, this weed was intentionally planted in gardens, but has now escaped and is very difficult to control
  • Grows in moist or marshy sites along streams or ditches, and in wetlands
  • Do NOT pull, dig, or cut the roots, as this may stimulate new growth
  • Chemical controls are needed

Russian Knapweed

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    • A perennial weed that spreads by root and seed
    • Grows two to three feet tall
    • Produces small pink, white, or lavender flowers during summer months
    • Upper part of root is dark brown to black in color
    • Grows in dense colonies along roadsides, riverbanks, and ditches, and in pastures and waste places
    • Cut or mow prior to seed set to reduce current year's growth; will not kill plants
    • Chemical controls are needed

Scotch Thistle

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    • A biennial weed that spreads by seed only
    • Grows up to 12 feet tall
    • Violet to reddish flowers are 1 to 2 inches in diameter
    • Stems have broad, spiny wings
    • Plant has a grayish appearance and is very spiny
    • Grows in along roadsides and in waste places and disturbed soils
    • Dig, removing the top two inches of root prior to seed set
    • Chemical controls are available

Spotted Knapweed

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    • A biennial to short-lived perennial weed that spreads by seed only
    • Grows one to three feet tall, sometimes taller
    • Produces small pink, white, or lavender flowers during summer months
    • Bracts below flower head have dark spots but are not spiny
    • Grows in disturbed soil, rangelands, pastures, meadows and roadsides
    • Cut or mow prior to seed set to reduce current year's growth, or dig, removing the top 2-6 inches of root
    • Chemical controls are available

Yellow Flowers

Yellow Starthistle

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  • An annual to short-lived weed that spreads by seed only
  • Grows one to three feet tall
  • Bright yellow flower heads are about 1 inch in diameter
  • Inch-long spines form at ends of bracts under flowerheads
  • Stems are winged, but not spiny
  • Grows along roadsides and in waste areas and grasslands
  • Pull, dig or mow at first sign of yellow flowers
  • Chemical controls are available

Curlycup Gumweed

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    • Biennial or short-lived perennial
    • Grows 1 to 3 feet tall with fibrous root systems
    • Leaves are about one inch long, rounded at the tip, toothed on the edges and grow alternately on the stem
    • Yellow flowers are about one inch in diameter and sticky or gummy underneath
    • Commonly seen growing along roadsides
    • Difficult to remove by hand or weed wacker
    • Herbicides are available

Dalmatian Toadflax

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    • A perennial that spreads by roots and seeds
    • Grows up to 3 feet tall
    • Has yellow flowers that resemble snapdragons
    • Leaves are heart-shaped and clasp the stem
    • Grows along roadsides and in rangelands or pastures
    • In the past, this weed was intentionally planted in gardens, but has now escaped and is very difficult to control
    • Pull or dig for several years, removing as much root as possible.
    • Mowing is not effective and may spread the weed
    • Chemical controls are available

Mullein

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  • Biennial
  • Grows 2 to 6 feet tall
  • Grayish-green in appearance with fuzzy leaves and stem
  • Leaves grow alternately and are prominently veined
  • Yellow flowers appear on long terminal spikes that form at the top of the plant
  • Remove prior to seed set by pulling, hoeing or mowing,
  • Easiest to pull during the first year of growth
  • Herbicides are available.

Puncturevine

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  • Annual
  • Forms flat, spreading mat with stems up to 5 feet long
  • Leaves are small and include 4 to 8 pairs of leaflets
  • Flowers are tiny, yellow, and have 5 petals
  • Produces many spiny fruits that break apart into tack-like "goatheads" that can puncture tires and feet
  • Plant continues to flower and produce seed until frost
  • Remove prior to seed set by pulling, hoeing or digging; easiest when plant is small
  • Herbicides are available.

Sweetclover

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  • Annual or biennial
  • Grows up to 6 feet tall and as wide
  • Small three-lobed leaves
  • Sometimes confused with alfalfa
  • Flower spikes are 2 to 6 inches long, with many small flowers
  • Both yellow and white sweetclover are found locally
  • Used in seed mixes for erosion control
  • Remove prior to seed set by pulling, hoeing or mowing

White Flowers

Diffuse Knapweed

Perennial Pepperweed

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  • A perennial that spreads by roots and seeds
  • Grows to six feet tall
  • Produced white flowers resembling baby's breath in June
  • Leaves are lance-shaped
  • Grows along streamsides, meadows, pastures, floodplains, and roadsides and forms dense colonies.
  • Do NOT pull, dig, or cut the roots as this may stimulate new growth
  • Chemical controls are needed.

Blue Flowers

Chicory

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  • A many-branched perennial
  • Grows up to 6 feet tall from a deep taproot
  • Lower leaves are deeply toothed
  • Upper leaves are sparse and small, giving the plant a stemmy look
  • Many sporadic flowers are white to bluish-purple and up to 1 inch in diameter
  • Contains a milky juice
  • Remove prior to seed set by pulling, hoeing or mowing
  • Herbicides may be needed

Other

Broadleaf and Buckhorn Plantain

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  • Perennials
  • Often found growing in lawns
  • Leaves vary in width between species (broadleaf has wider leaves, buckhorn narrower)
  • All have prominent parallel veins in leaves
  • A central flowering stem sends up long, flowering spike
  • Remove prior to seed set by pulling or hoeing
  • Herbicides may be needed

Curly Dock

Kochia

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  • Annual
  • Grows 1 to 6 feet tall
  • Stems are highly branched
  • Leaves grow alternately, are lance-shaped, and about 2 inches long
  • Leaves are hairy underneath with a smooth upper surface
  • Flowers grow among the upper leaves inconspicuously, and form short spikes at the top of the plant
  • Remove prior to seed set by pulling, hoeing or mowing
  • Easily controlled mechanically in the seedling stage
  • Herbicides are available

Redroot Pigweed

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  • Annual
  • Grows 2 to  6 feet tall
  • Lower stems are red or red-striped, as is the root
  • Leaves have prominent veins and are somewhat lance-shaped
  • Flowers grow in spike-like clusters that have stiff, spine-like scales
  • Seeds are black and shiny
  • Remove prior to seed set by pulling, hoeing or mowing
  • Herbicides are available

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