1. Canada Thistle

    Cirsium arvense Canada Thistle - A rhizomatous, perennial, herbaceous plant that grows 2-5 feet tall, usually branching only near the top of the plant.Leaves: Leaves are alternate and lance to narrowly oval in shape, possessing short spines along the leaf edges.Flowers: Flowers bloom from May-October. Many flowerheads clustered towards the tip of the stem, purple to pink in color.Habitat: Common in pastures and croplands. Can also invade wet areas as well like steam banks, sedge meadows, and wet prairies.Weed Classification: C SelectWhy is it a Noxious Weed?Once established, it can spread vigorously and replaces native plants. It also lowers crop …


    Weed Control - Oct. 6, 2022, 9:32 a.m.


  2. Oxeye Daisy

    Leucanthemum vulgare Oxeye Daisy - A perennial, herbaceous plant growing 1-3 feet tall.Leaves: Leaves are alternate and lance-shaped, with toothed or lobed edges.Flowers: Flowers bloom from May-October. Single flowerhead at the end of the stem. It has many white ray-flowers, creating the "petals," and yellow disc-flowers in the middle.Habitat: Found in grasslands, overgrazed pastures, waste areas, meadows, roadsides, railroad ROWs, yards, and fields.Weed Classification: CWhy is it a Noxious Weed?It can aggressively invade fields and decrease plant diversity. It decreases crop yield and has rhizomes with adventitious roots.Oxeye Daisy is very common in Lewis County. It can be hard to …


    Weed Control - Oct. 6, 2022, 9:32 a.m.


  3. Yellow Toadflax

    Linaria vulgaris Yellow Toadflax - A perennial growing 8-31 inches tall from creeping roots. Forms colonies.Leaves: Many narrow, linear leaves up to 4 inches in length, alternating along the stem.Flowers: Flowers bloom from June-September. Many flowers crowd the top 2-9 inches of the plant. Flowers are yellow, hairy, and have orange "throats." Resembles snapdragons.Habitat: Grows in a variety of habitats, including: roadsides, edges of fields, rangelands, meadows, cultivated fields, and waste areas.Weed Classification: CWhy is it a Noxious Weed?It can easily invade range and farmlands outcompeting desirable crops/forage. Livestock will rarely eat the plant.Yellow Toadflax can infest cultivated land easily, …


    Weed Control - Oct. 6, 2022, 9:33 a.m.


  4. Himalayan Knotweed

    Persicaria wallichii Himalayan Knotweed - A clumping perennial with hollow stems and creeping rhizomes. It grows about 6 feet in height.Leaves: Leaf shape is elongated compared to other knotweeds and are around 5-12 inches in length. They are leathery and alternate along the stem.Flowers: Flowers bloom from July-October. Whiteish pink flowers that are fragrant grow at the tips of branches.Habitat: Grows in disturbed, moist sites like roadsides, riparian, and wetland areas.Weed Classification: B DesignateWhy is it a Noxious Weed?This plant vigorously grows into dense stands that overtake native vegetation and alter ecosystems. It can survive severe floods and spread plant …


    Weed Control - Oct. 5, 2022, 4:16 p.m.


  5. Curlyleaf Pondweed

    Potamogeton crispus Curlyleaf pondweed - The entire plant stays underwater, except for the flower stalk, and usually only grows in the spring before dying off in the late summer.Leaves: Leaves are alternate along the stem, submerged, and oblong in shape. They are also stiff with distinctly wavy edges and fine teeth.Flowers: Flowers bloom from June-August. Flowers are very small and have 4 petal-like lobes.Habitat: Grows in shallow or deep water that can either be still or flowing and tolerates disturbances.Weed Classification: C SelectWhy is it a Noxious Weed?This plant can form dense colonies on the surface that interfere with aquatic …


    Weed Control - Oct. 5, 2022, 4:38 p.m.


  6. Stewardship Incentive Program

    Introductory materials, offering all the details you need to navigate the process, can be found here:2026 SIP Program: IntroductionPlease review these instructions in their entirety.To apply: 2026 SIP ApplicationPlease complete the form to the best of your ability and submit it back to us via email or paper mail.Our mailing address is: 351 NW North St., Chehalis WA 98532Our office email is weeds@lewiscountywa.govThe SIP's Pesticide License Reimbursement application can be found here:2025 SIP Pesticide License Reimbursement ApplicationResidents may participate in both aspects of the program simultaneously. Acceptance into one will not negatively affect the application status for the other.Note: A …


    Weed Control - March 1, 2023, 4:28 p.m.


  7. Hawkweeds

    Hieracium spp. Orange Hawkweed Mouseear Hawkweed Hawkweeds - Most hawkweed species are hairy and have a milky latex in their stems.Leaves: Most species will have basal leaves. Stem leaves can vary by subgenus. Leaves can be smooth, toothed, or lobed.Flowers: Blooms typically May - Sep. Most non-native species will have yellow ray flowers, but some species can have orange flowers as well. Flowers looks similar to dandelion flowers.Habitat: Typically found in fields, meadows, pastures, forest clearings, and disturbed areas like roadsides and abandoned farmland.Weed Classification: B DesignateWhy is it a Noxious Weed?The plants are invasive, spread easily, and negatively impact …


    Weed Control - Sept. 29, 2022, 9:47 a.m.


  8. Hydrilla

    Hydrilla verticillata Hydrilla- Very similar in appearance to our native elodea (Elodea canadensis) and to Class B noxious weed Brazilian elodea (Egeria densa), this aquatic perennial is especially problematic in waterways and attempts to mechanically control will often perpetuate its spread.Hydrilla vs Native Elodea fact sheet from the New Jersey Water Supply AuthorityLeaves: Whorled formation of 3-10 (but most often 5) leaves with sharply toothed margins. There are often spines along the reddish midrib giving the plant a "velcro" feeling when pulled.Flowers: Transparent to white, female flowers with petals of 3 are attached to the stem tip by a slender …


    Weed Control - Sept. 26, 2022, 1:13 p.m.


  9. Yellow Archangel

    Lamiastrum galeobdolon Yellow Archangel - Evergreen to semi evergreen plant that grows very quickly. It is mostly a trailing perennial, though it can grow upright if climbing other plants.Leaves: Opposite and oval shaped. Toothed and hairy typically with silver-gray markings.Flowers: Flowers bloom from April through June. Flowers are small, yellow, and two lipped. The upper lip is hooded, and the lower lip has orange/brown markings. Flowers grow in whorls.Habitat: Yellow Archangel can grow in shade or sunlight. Can sometimes escape people's landscaping into nearby forests, greenbelts, and riparian habitats.Weed Classification: B SelectWhy is it a Noxious Weed?Escapes easily from gardens …


    Weed Control - Sept. 29, 2022, 9:49 a.m.


  10. False Brome

    Brachypodium sylvaticum False Brome - A perennial, loosely tufted grass with upright stems.Leaves: Leaf sheathes have spreading hairs (can be hairless). Leaf blades are flat and arched up to 14 inches long. Leave blades are covered with long soft hairs.Flowers: Flowers bloom from April-June. Flowers are grouped in upright to nodding spikes. Flowers vary in hairiness and typically don't have stalks connecting them to main stem.Habitat: Grows in a variety of habitats including: forests, forest edges, woodlands, riparian areas, prairies, and roadsides.Weed Classification: AWhy is it a Noxious Weed?It spreads very fast and outcompetes native flora. Can form dense monocultures …


    Weed Control - Sept. 29, 2022, 10:46 a.m.