The Most Common Lawn Weeds in Idaho

a lot of flowers of oxeye daisy

Weeds are the party crashers of your beautiful, native landscape. They outcompete your desirable plants and absorb most of the beneficial nutrients. Identifying the most common weeds in Idaho helps you minimize an overwhelming invasion. 

Weeds have the annoying habit of popping out in your backyard, even if you’ve planted the right grass seed at the right time (here’s the best time to plant grass seed in Idaho). Some weed species are low-growing, meaning they can hide underneath your tall flowers or shrubs. We’ll uncover 8 of Idaho’s most common weeds, the conditions in which they thrive, and how to identify them. 

8 Common Lawn Weeds in Idaho

There are hundreds of invasive plant species in the US, but here are some of the worst weeds on the Gem State’s most wanted list:

1. Dandelion (Taraxacum officinale)

Dandelion (Taraxacum officinale)
GT1976 | Wikimedia Commons | CC BY-SA 4.0

Dandelion is a short-lived, perennial weed that grows up to 3 feet long. It is commonly found in lawns, roadsides, and unmanaged properties. Dandelions spread from the root and root segments, with each plant able to produce up to 20,000 viable seeds. Strong winds can easily carry these seeds due to their feathery parachutes.

  • Weed type: Broadleaf
  • Life cycle: Perennial 
  • Where it thrives: Full sun, can adapt to any soil
  • How to identify: Look for the flat yellow flowers that appear on your lawn in the spring. The leaves have jagged edges and leafless stems. Dandelions release a milky white juice when cut.

2. Canada Thistle (Cirsium arvense)

pink flowers of canada thistle
Matt Lervin | Flickr | CC BY 2.0

Canada thistle is an aggressive weed that hinders the growth of your desirable, native plants. Each plant produces up to 5,300 seeds which can remain viable for almost a decade. Thistle plants spread primarily through seed dispersal by wind, water, and human activities. 

  • Weed type: Broadleaf
  • Life cycle: Perennial
  • Where it thrives: Full sun or partial shade; tolerates a variety of soil conditions but doesn’t like wet feet.
  • How to identify: Canada thistle grows up to 3 feet tall. It has spiny leaves and produces purplish-pink flowers. 

3. White Clover (Trifolium repens)

White clover (Trifolium repens)
Matt Lavin from Bozeman, Montana | Wikimedia Commons | CC BY-SA 2.0

Despite having vegetative qualities, white clover is among Idaho’s most common lawn weeds. The perennial legume spreads by both seed and stolons, stealing water and nutrients from your desirable plants. To make matters worse, white clover attracts pocket gophers that wreak havoc on your lawn.

  • Weed type: Broadleaf
  • Life cycle: Perennial 
  • Where it thrives: Areas with full sun exposure, but can adapt to shady lawns.
  • How to identify: White clover has a stoloniferous growth habit. Its leaves have three leaflets that may have water marks on the upper surface. The flower heads have up to 100 florets and are borne on long stalks from the leaf axils. 

4. Field Bindweed (Convolvulus arvensis)

close up of bindweed flower
Peter O’Connor aka anemoneprojectors | Wikimedia Commons | CC BY-SA 2.0

Field bindweed is a perennial plant that grows in circular patches and creeps in every direction. It primarily spreads by seed until it reaches maturity, after which it spreads by extending lateral roots. Bindweed infestations occur when root sections are transported by lawn equipment from one spot to another. 

  • Weed type: Broadleaf
  • Life cycle: Perennial
  • Where it thrives: Full sun and dry areas with gravelly field soils. 
  • How to identify: Field bindweed has twining stems that grow up to 6 feet tall. The green leaves are arrow-shaped and are sometimes covered with a whitish powder. The funnel-shaped flowers are often white or pinkish. 

5. Black Medic (Medicago lupulina)

Black medic weed
Andreas Rockstein | Flickr | CC BY-SA 2.0

Black medic is a perennial legume that grows low to the ground and forms patches up to 2 feet wide. The low growth habit helps it survive mowing, making it a tough-to-eliminate lawn weed. A single black medic plant can produce as many as 6,600 seeds annually. They can remain viable in your soil for several years.  

Bullet points 

  • Weed type: Broadleaf
  • Life cycle: Perennial plant in areas with mild winters, though mainly a shallow-rooted annual. 
  • Where it thrives: Lawns with full sun and compact soils.
  • How to identify: Black medic has black seed heads and heart-shaped leaves. The flowers are yellowish and often grow in clumps. 

6. Common Chickweed (Stellaria media)

Common chickweed (Stellaria media)
Robert Flogaus-Faust | Wikimedia Commons | CC BY 4.0

Common chickweed is an edible plant that likes to grow in flower beds, ornamental plantings, and areas with rich soils. It reproduces mainly from seeds that remain viable in the soil for up to 30 years. Given it’s a winter annual, chickweed grows vigorously in cool temperatures. In addition to out-competing your desirable plants, chickweed attracts insect pests such as Western tarnished plant bugs. 

  • Weed type: Broadleaf 
  • Life cycle: Annual, but can also grow as a short-lived perennial
  • Where it thrives: Moist, cool conditions and fertile soils with neutral pH
  • How to identify: Chickweed has a low-growing habit, making them appear like mats. It has a slender stem with smooth and shiny leaves. Chickweed produces white-shaped flowers with 5 petals. 

7. Orange Hawkweed (Hieracium Aurantiacum)

closeup of Orange hawkweed plant
Cbaile19 | Wikimedia Commons | CC0 1.0

Orange hawkweed is one of the worst weeds that can grow on your lawn. It is highly invasive with prolific seed production and vigorous vegetative growth. Once found in your garden, hawkweed can spread by wind-dispersed seeds or water-dispersed stolons. Unfortunately, mowing and hand-pulling cannot eliminate a hawkweed invasion. 

  • Weed type: Broadleaf
  • Life cycle: Perennial
  • Where it thrives: Full sun or partial shade. Hawkweed prefers well-drained soils with a coarse texture. 
  • How to identify: Hawkweed grows up to 2 feet tall. The leaves appear like basal rosettes. Orange-red flowers are found at the end of the leafless flower stalks. 

8. Oxeye Daisy (Leucanthemum vulgare)

couple of flowers of oxeye daisy
GT1976 | Wikimedia Commons | CC BY-SA 4.0

Oxeye daisy is a herbaceous perennial that competes aggressively with native plants in your lawn. Branched rhizomes and adventitious roots allow this non-native weed to spread rapidly in unmaintained lawns. The yellow center of daisies attracts pollinating insects such as bees and hoverflies, which can be problematic for a family member allergic to bee stings. 

  • Weed type: Broadleaf
  • Life cycle: Perennial
  • Where it thrives: Oxeye daisy thrives in full sun and well-drained soil. It can also grow in partially shaded lawns. 
  • How to identify: It grows up to 3 feet tall. The stem can produce 2 or more flower heads. The leaves are spoon-shaped and partially wrap around the stem. The flowers bloom all summer with 2-inch wide yellow centers. 

FAQ About Idaho Lawn Weeds

Does johnsongrass grow in all parts of Idaho? 

Johnsonsongrass is an invasive, grassy weed species in Idaho. Here are some of the counties in which Johnsongrass grows: 

  • Oneida
  • Caribou
  • Bingham
  • Boundary
  • Kootenai
  • Clearwater

Where is chickweed mostly found in Idaho? 

Chickweed grows mostly in western parts of the state, including the following counties: 

  • Owyhee
  • Adams
  • Latah
  • Bonner
  • Boise

Is matgrass native to Idaho? 

It most definitely is not. Matgrass is considered an invasive species to Idaho lawns. It is challenging to control given its close resemblance to other grasses in mixed stands. 

Hire a Pro to Stamp Out Weeds

Most invasive lawn weeds including dandelions are noticeable once fully established. Hand-pulling and other manual controls may encourage further spreading via rhizomes or stolons, essentially working in the weeds’ favor. When you need reinforcements, hire a local weed control company to liberate your native garden from unwanted weeds.

Main Image Credit: H. Zell | Wikimedia Commons | CC BY-SA 3.0

Jeffery Keusseyan

Jeffery Keusseyan brings his passion for nature into his love of writing to produce fun, informative content. With thorough research and hands-on experience, he provides readers with varoius lawn mowing tips and landscaping ideas.