• Utah State Univ.

  • 2076 N 1200 E

     No. Logan, UT 84341

    Tel. (435) 752-1310
    Fax (435) 752-1357

    Normal Office Hours
    Monday to Friday
    8:00am to 5:00pm


    North Logan is home to a diverse set of plants and animals. However, several species of flora are noxious and even hazardous to humans and animals. Although not an exhaustive list, the following plants are a threat to North Logan City and the Cache Valley environment:


    For more information and pictures, please click on the plant name and picture respectively.

    Class A Weeds

    Early Detection and Rapid Response (EDRR) 
    These species are highly invasive and pose the highest threat.

    Diffuse Knapweed

    Also Known as White Knapweed or Tumble Knapweed

    An invasive biennial plant with a large taproot. The plant can spread through contaminated alfalfa, animals, and as a tumbleweed. Herbicides, biocontrol agents, and tilling can control the weed. Herbicides should be applied during the rosette to pre-bud stage. Native plants should be planted in place of removed Diffuse Knapweed to diminish regrowth.
    The root must be destroyed or the plant will likely reestablish itself.

    Image is in the Public Domain.


    Leafy Spurge

    Also Known as Green Spurge

    A perennial plant which is aggressively invasive to America. Every part of the plant contain a toxic white milky sap which can kill cattle. Seeds can remain viable for at least seven years. Leafy Spurge has a complex, and very large, root system that can propagate the plant even from small pieces of root.
    This weed is extremely difficult to destroy but can be managed with herbicides followed by biocontrol.

    Photo by Ivar Leidus under the Creative Commons Attribution-Share Alike 3.0 Unportedlicense.

    Purple Loosestrife

    Also Known as Spiked Loosestrife or Purple Lythrum

    This invasive aquatic plant that can cause dramatic water blockage in rivers and canals while crowding out native flora and fauna. The ecological disruption of the this plant comes from its aggressive reproduction through seeds and root systems. 
    Herbicides can offer good control whereas biological control offers excellent means to destroy the plant.

    Photo by Liz West under the Creative Commons Attribution 2.0 Genericlicense.


    Yellow Starthistle

    Also Known as Golden Starthistle, Yellow Cockspur, or Barnaby Thistle

    The Yellow Starthistle is an invasive, thorny weed which eliminates other plants, degrades ecosystems, prevents agricultural grazing, and the movement of indigenous animals. The lack of herbivores which co-evolved with the plant make the star-thistle particularly effective in propagating without control.
    Tillage, chemicals are effective control. Grazing by livestock while the plant is not in its spiny stage are effective ways to control the weed.

    Image is in the Public Domain.

    Class B Weeds

    Noxious weeds which pose a threat to the state and have a hight priority to control.

    Dyer's Woad

    Also Known as the Asp of Jerusalem

    A plant used once for dyeing clothes in Europe, this invasive weed has a tap root of up to 5 feet deep. Heights range from 1 to 4 feet tall with bright yellow flowers. 
    Rust fungus is an effective biocontrol which spreads naturally. Herbicides are most effective when applied to rosettes in spring, fall, and during pre-bloom. Digging up the plant is also a fair control for the weed if followed by biocontrol with native plants.

    Photo by Pethan under the Creative Commons Attribution-Share Alike 3.0 Unported license.

    Hoary Cress

    Also Known as Whitetop

    A perennial weed which propagates by seed and horizontal creeping roots. The stem is covered in soft hairs and the leaves follow the stem from base to flower.
    Biocontrol is still in development while herbicides can offer fair to good control.

    Photo by Radio Tonreg under the Creative Commons Attribution 2.0 Generic license.







    Perennial Pepperweed

    Also Known as Broadleaved Pepperweed, Pepperwort, Peppergrass, Dittander, Dittany, and Tall Whitetop.

    An invasive, yet edible plant which produces pepper-like seeds and white flowers. It's complex root system can constitute 40% of the plant's mass and reach 9 feet deep. This plant is a threat to wetland habitats and other ecosystems. 
    Although biocontrol is still in early stages, the plant can be controlled best by certain herbicides applied to growing plants.

    Photo by Michael Becker under theCreative Commons Attribution-Share Alike 3.0 Unported license.


    Poison Hemlock

    Also Known as Conium, Hemlock, Devil's Bread, Beaver Poison, Musquash Root, Poison Parsley, Spotted Cororbane, and Keckies.

    A highly poisonous perennial weed known for its toxic properties which cause respiratory collapse and death. Even small doses (only 6-8 fresh leaves or fresh roots) can be fatal to adults. Grazing livestock can be killed by the plant, also as every part of the plant is poisonous.
    Herbicides offer the best control when applied to actively growing plants. Biocontrol is also available.

    Image is in the Public Domain.

    Class C Weeds

    Noxious weeds which pose a threat to the agricultural industry.

    Canada Thistle

    Also Known as Creeping Thistle, Lettuce From Hell Thistle, California Thistle, Corn Thistle, and other names.

    Known for its characteristic purple flowerhead during summer, this thistle is versatile and can crowd out natural vegetation and contaminate crop. It spreads through wind-borne seeds and underground rhizomes.
    Tillage is not effective as the plant will certainly grow back. Herbicides applied while the plant is growing from spring to fall offer good control.

    Photo by Ivar Leidus under theCreative Commons Attribution-Share Alike 3.0 Unported license.


    Field Bindweed

    Also Known as Morning Glory, and Wild Morning Glory.

    A bindweed which strangles and destroys other plants and is extremely persistent. Root systems can grow as far as 10 feet deep and is used to propagate the plant. The seeds also are very hard to control as they can remain viable in soil for decades. It is also mildly toxic to grazing animals.
    Eradication is difficult as the seeds and roots are extremely persistent. Herbicides applied from late spring to killing frost is most effective for controlling this insidious weed.

    Photo by Bouba under the Creative Commons Attribution-Share Alike 3.0 Unported license.

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