Common Weeds in Illinois and How to Get Rid of Them

closeup of a thistle plant

In the Land of Lincoln, uncontrolled weeds like crabgrass and dandelions, can quickly overrun lawns. Identifying common Illinois weeds and knowing how to get rid of them with manual or chemical methods can help you maintain a beautiful, weed-free landscape.

Weeds can negatively impact the look of your lawn and the wellbeing of your plants by competing for resources. Despite their drawbacks, some weeds benefit the local ecosystem and soil. Among the best ways to control weeds are mowing, hand-pulling, using herbicides, and maintaining a healthy lawn.

KEY TAKEAWAYS

  • Understanding the specific type of weed you’re dealing with is crucial for effective management.
  • Weeds can be controlled through various methods, including mechanical control (like mowing and hand-pulling), and chemical control (like herbicides).
  • Despite being problematic, some weeds have benefits: Dandelions and cat’s ear are edible, while clover and lambsquarter serve as a food source for insects and birds.

Weeds Common to Illinois

Bindweed (Convolvulaceae family)

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

Bindweed is a tough, perennial vine found throughout the Prairie State. It has long stems, arrowhead shaped leaves, and trumpet-like flowers. There are two main types of bindweed: hedge bindweed (Calystegia sepium), which contains some subspecies that are native plants in Illinois, and field bindweed (Convolvulus arvensis), a native of Eurasia. 

Bindweed likes places with well-drained soil that get a lot of sun. It is often found in lawns with thinning or patchy grass, using the gaps to grow. Because of its deep root system, this pernicious weed can be difficult to get rid of.

  • Weed type: Vine
  • Life cycle: Perennial

How to manage bindweed:

  • Mechanical control: Regular mowing helps manage bindweed, but fully eliminating it is difficult due to its extensive root structure. Repeatedly cutting the plant below soil level can disrupt photosynthesis, leading to the plant’s death.
  • Chemical control: Post-emergent herbicides such as 2,4-D, carfentrazone, quinclorac, dicamba, oxyfluorfen, and triclopyr can control bindweed. For spot applications, glyphosate can be used, but caution is necessary if bindweed is growing among other plants.

Bittersweet nightshade (Solanum dulcamara)

closeup of Bittersweet nightshade plant
Andreas Rockstein | Flickr | CC BY-SA 2.0

Nightshade plants are identified by their small, star-shaped flowers, and their berries are often poisonous. Bittersweet nightshade is commonly found in the northern half of Illinois, especially in the northeast. These plants grow rapidly, outcompeting other plants and potentially reducing biodiversity.

Nightshade can pose a significant problem as this and other plants are toxic to dogs, cats, and people if consumed. The berries of this plant can be tempting for kids and pets, so you should remove these plants quickly.

Pro tip: Eating poisonous nightshade berries can result in symptoms such as nausea, vomiting, and confusion. If you suspect someone has ingested them, immediately call 9-1-1 or the U.S. National Poison Help hotline at 1-800-222-1222.

  • Weed type: Broadleaf
  • Life cycle: Perennial

How to manage nightshade:

  • Mechanical control: Regular mowing and hand-pulling can help manage this weed, but these methods are often insufficient due to its rapid spread and deep root system.
  • Chemical control: Post-emergent herbicides containing glyphosate can be effective in controlling nightshade.

Cat’s ear (Hypochaeris radicata)

closeup of Cats ear plant
Andreas Rockstein | Flickr | CC BY-SA 2.0

Cat’s ear, also known as false dandelion, often gets mistaken for dandelions because of its similar yellow flowers. Unlike dandelions, cat’s ear has multiple flowers on a single stalk and hairy leaves with lobed edges. 

Although cat’s ear is a resilient plant, capable of growing well in various types of soil, you most often find this plant around the counties of Champaign and St. Clair in northeastern Illinois. While it is dangerous for horses, this plant is entirely edible for people. Its leaves, in particular, are often used in salads.

  • Weed type: Broadleaf
  • Life cycle: Perennial

How to manage rough cat’s ear:

  • Mechanical control: Remove the plant by digging as soon as the leaves appear; focus on the taproot.
  • Chemical control: For large infestations, herbicide treatment is often required. The best post-emergent herbicides, when used as directed, will not harm established grass. They are most effective when applied to the plant’s rosette before flowering, typically in the spring or fall.

Chicory (Cichorium intybus)

closeup of Chicory plant, with blue flowers
Andreas Rockstein | Flickr | CC BY-SA 2.0

Chicory can be a winter annual or a biennial plant. This herb is characterized by light blue flowers and small narrow leaves. While the flowers are pretty, chicory can become a major weed problem for homeowners in almost every part of Illinois. This plant spreads in yards with common lawn problems, like bare spots. Mowing often won’t kill the plant as it can regrow from the taproot.

Chicory often grows in fields, along roadsides, and in lawns. The roots of this plant have been used as a coffee substitute or additive, particularly during the Great Depression and World War II, when coffee was either too expensive or unavailable.

  • Weed type: Broadleaf
  • Life cycle: Annual or biennial

How to manage chicory :

  • Mechanical control: Maintain a healthy lawn to eliminate chicory. Your turfgrass can outcompete it when you know how to fertilize and water properly. Mowing at a higher level can shade this weed out. When removing manually, make sure to extract the entire root.
  • Chemical control: For a large infestation of chicory, consider using a post-emergent herbicide. Glyphosate isn’t effective for these plants, so look for a 3-way broadleaf herbicide.

Clover (Trifolium)

a field of white clover weeds
White clover
Matt Lavin | Wikimedia Commons | CC BY-SA 2.0

There are several types of clover in Illinois, but white clover (Trifolium repens) and red clover  (Trifolium pratense) are what most homeowners deal with in their yards.  White clover is recognized by its shamrock-shaped (trifoliate) leaves and white flower heads, while red clover has larger purplish-pink flowers. Compacted soil, mowing too low, or overwatering are a few reasons why clover is invading your lawn

Clover is an aggressive plant found throughout the Prairie State. It tends to outcompete grass, posing a challenge for those who prefer their turfgrass neat and tidy looking. It thrives in cool, moist climates with well-drained soils. Despite being labeled a weed, clover lawns have regained popularity due to their low-maintenance needs. They are also eco-friendly, as clover flowers provide early food for bees in spring.

  • Weed type: Broadleaf
  • Life cycle: Perennials, biennials, and annuals

How to manage clover:

  • Mechanical control: Pulling the plants by hand or with a weeding tool is a non-toxic way to kill weeds and works well for small patches of clover.
  • Chemical control: To get rid of clover in your lawn, you may need to use post-emergent herbicides. Opt for a systemic herbicide that will kill the roots and the plant.

Common burdock (Arctium minus)

closeup of the common burdock
Zeynel Cebeci | Wikimedia Commons | CC BY-SA 4.0

Burdock is a biennial weed characterized by large, heart-shaped leaves and round burrs that can cling to clothing and animal fur. It bears purple flowers arranged in clusters, can grow to 6 feet tall, and are frequently found in disturbed areas such as roadsides, pastures, or abandoned fields.

While burdock is a common non-native plant in central and northern Illinois, it is less common in the southern part of the state. Burdock reproduces through seed dispersal, and interestingly enough, Velcro was inspired by the burr’s hook-and-loop attachment design.

  • Weed type: Broadleaf
  • Life cycle: Biennial

How to manage common burdock:

  • Mechanical control: Regular mowing can help manage this plant. For a more effective approach, you can dig or slice through the taproot about 3 to 4 inches below the soil level. Moisten the soil beforehand to make this task easier.
  • Chemical control: Pre-emergent herbicides such as glyphosate, 2,4-D, dicamba, or clopyralid can control burdock. Post-emergent herbicides can work if used before the rosettes form.

Crabgrass (Digitaria sanguinalis)

close-up of crabgrass along the edge of a lawn
NY State IPM Program at Cornell University | Flickr | CC BY 2.0

Crabgrass is like an uninvited party guest who barges in and tries to take over the place. This fast-growing weed has a low growth habit, extending outward like a crab’s legs, and spreads rapidly, with wide leaves and seed heads. It’s important to get rid of crabgrass because it competes with your turf for resources and ruins your lawn’s look with its wild growth.

Crabgrass is common in Illinois, found both in suburban lawns and agricultural fields. It does well in hot, dry conditions and in compacted soils, where regular lawn grasses struggle. In some parts of the world, it’s grown as a grain crop and for animal feed.

  • Weed type: Grass
  • Life cycle: Summer annual

How to manage crabgrass:

  • Mechanical control: Regularly mowing at a higher height (above 3 inches) will shade the soil and help prevent crabgrass seeds from germinating due to the absence of sunlight. Aerate compacted soil in early fall, and hand-pull plants before they go to seed. Prevent crabgrass from spreading by overseeding bare or thin spots in the lawn.
  • Chemical control: Crabgrass preventers, which are pre-emergent herbicides, are used before the crabgrass sprouts. If crabgrass is already present in the lawn, post-emergent crabgrass killers are available.

Creeping Charlie (Glechoma hederacea)

close up of creeping charlie
Frank Mayfield | Flickr | CC BY-SA 2.0

In Illinois, a pervasive problem for many homeowners is creeping Charlie, also known as ground ivy. This perennial weed, easily recognized by its scalloped leaves and small purple flowers, grows low and spreads rapidly. Through its creeping stems (stolons), it can quickly overrun lawns.

Creeping Charlie typically thrives in shady lawns with rich soil and poor drainage, often pushing out other plants as it takes control. Some people enjoy it as a ground cover with purple flowers and mint-scented leaves.

  • Weed type: Vine
  • Life cycle: Perennial

How to manage creeping Charlie:

  • Mechanical control: Regular mowing at a higher level can help manage this weed, but it is often insufficient due to its rapid spread. Hand-pulling can be effective if done repeatedly over time.
  • Chemical control: Post-emergent broadleaf herbicides containing dicamba or triclopyr are recommended for controlling creeping Charlie.

Dandelion (Taraxacum officinale)

person holding yellow dandelion in a hand
Pexels

Dandelions, a perennial weed, are a common sight on Illinois lawns. They have a rosette of toothed leaves, a hollow stem, and their bright yellow flower eventually turns into a puffball of seeds. These plants can adapt to various soil conditions, but they typically favor full sun exposure and moist, fertile soil.

Despite their reputation as weeds, there are benefits of dandelions in your yard. They are highly nutritious, a food source for pollinators, and have been used in herbal medicine for centuries. They are rich in vitamins and minerals, often used in salads, and grown as part of an edible herb garden.

  • Weed type: Broadleaf
  • Life cycle: Perennial

How to manage dandelions:

  • Mechanical control: Regular mowing, leaving grass at 3 inches or above, can help suppress dandelion growth. An effective way to get rid of dandelions is to remove the entire taproot from the ground, which can be done using a dandelion digger.
  • Chemical control: A broadleaf systemic herbicide like 2,4-D, dicamba, or MCPP will kill the taproot to prevent the dandelion from re-growing.

Lambsquarter (Chenopodium album)

lambsquarter plant
Andreas Rockstein | Flickr | CC BY-SA 2.0

Lambsquarter, or goosefoot, is a common weed in Illinois. It has diamond-shaped leaves with toothed edges, and the leaves often have a white, powdery layer on the underside. The plant also has small green flowers that bunch up at the top. Lambsquarter can quickly take over a lawn or garden. High salt content in the soil from deicing can explain why you have weeds like lambsquarter in your lawn.

Lambsquarter can be a tall weed in Illinois, growing between 4 inches up to 6 feet tall in the right conditions. However, it actually serves a vital role by providing sustenance and shelter for various insects and beneficial birds. Additionally, its young leaves and stems are edible. They can be added to salads and have been used as a leafy vegetable in numerous cultures.

  • Weed type: Broadleaf
  • Life cycle: Summer annual

How to manage lambsquarter:

  • Mechanical control: Pull the plant out by hand, making sure to remove the entire root.
  • Chemical control: Pre-emergent herbicides such as pendimethalin or post-emergent herbicides like glyphosate can control lambsquarter.

Plantain (Plantago)

plantain weed on the ground
Broadleaf plantain
Robert Flogaus-Faust | Wikimedia Commons | CC BY 4.0

The broadleaf plantain (Plantago major) is commonly seen in northeast Illinois and sometimes in central Illinois. The buckhorn plantain (Plantago lanceolata) is typically found on drier sites, compacted soil, and struggling turfgrass across Illinois. Both can be recognized by their rosettes of leaves and small greenish flowers on a spike.

Broadleaf plantain has wide, oval-shaped leaves with several prominent veins, while buckhorn plantain has long, narrow leaves that resemble a lance or buck’s horn. Both types can become problematic in lawns due to their low growth habit and resistance to mowing.

  • Weed type: Broadleaf
  • Life cycle: Perennial

How to manage plantain:

  • Mechanical control: The entire plant, including all roots, should be removed from the ground.
  • Chemical control: To control broadleaf weeds like plantain, use post-emergent herbicides containing 2,4-D, dicamba, or MCPP.

Ragweed (Ambrosia)

many ragweeds on the ground
Common ragweed
Laval University | Wikimedia Commons | CC BY-SA 4.0

Ragweed, specifically the common ragweed (Ambrosia artemisiifolia) and the giant ragweed (Ambrosia trifida), is abundant in Illinois. The common ragweed is found throughout the state, whereas the giant ragweed is primarily found in the northern and central regions. They are recognizable by their small, star-shaped flowers and deeply lobed or divided leaves.

Ragweed pollen, a primary cause of hay fever, significantly affects those with allergies or asthma. Getting rid of ragweed can help create an allergy-free landscape. Its allelopathic properties, which release chemicals that hinder the growth of neighboring plants, make it a difficult weed to manage.

  • Weed type:  Broadleaf
  • Life cycle: Summer annual

How to manage ragweed:

  • Mechanical control:  Regular mowing and hand-pulling can help manage ragweed. However, it is essential to do this before the plant has a chance to produce and release its pollen.
  • Chemical control: Post-emergent herbicides containing glyphosate or 2,4-D can be effective in controlling ragweed.

Shepherd’s purse (Capsella bursa-pastoris)

closeup of Sheperd's purse with small delicate flowers
Tatiana | Wikimedia Commons | CC BY 4.0

Shepherd’s purse is a common cool-season wildflower in Illinois. It can be identified by its small white flowers and leafy rosettes. This plant is pervasive, appearing in various places —  from lawns and fields to sidewalk cracks. It can be difficult to get rid of Shepherd’s purse since it is quick to spread and can rapidly overrun a lawn.

A member of the mustard family, Shepherd’s purse is distinctive because of the unique shape of its seed pods, which resemble the leather purses used by shepherds during the Middle Ages.

  • Weed type: Broadleaf
  • Life cycle: Winter annual in most cases, but it is sometimes a summer annual

How to manage shepherd’s purse:

  • Mechanical control: Regular mowing and hand-pulling can help manage this weed. However, it’s crucial to remove the entire root system to prevent regrowth.
  • Chemical control: Both pre- and post-emergent herbicides can effectively control Shepherd’s purse. Herbicides containing 2,4-D or glyphosate are commonly used.

Spotted spurge (Euphorbia maculata)

closeup image of spotted spurge
Melissa McMasters | Flickr | CC BY 2.0

Spotted spurge, an annual weed, is prevalent across Illinois. This weed is adaptable and can flourish in a variety of environments, such as railways, roadsides, and landscapes. It’s regularly seen growing in cracks in the sidewalk and bare patches of lawn, making it a common sight in Illinois.

Spotted spurge is characterized by its small oblong leaves and a milky sap that can lead to skin irritation. The plant belongs to the Euphorbia genus, which includes around 2,000 species, including poinsettias, a poisonous plant to cats.

  • Weed type: Broadleaf
  • Life cycle: Summer annual

How to manage spotted surge :

  • Mechanical control: Regular hand-pulling can help manage spurge. It is important to remove the plant before it goes to seed in the fall. Wear gloves to protect your skin from the sap.
  • Chemical control: Post-emergent herbicides containing 2,4-D or glyphosate can be effective in controlling spurge.

Thistle (Cirsium)

closeup of a pink colored thistle plant
Ewan Munro | Flickr | CC BY-SA 2.0

Thistles, specifically Canada thistle (Cirsium arvense) and bull thistle (Cirsium vulgare), are prevalent in Illinois. They are identifiable by their lobed, spiny leaves and pink or purple flower heads and can be found invading lawns, pastures, and roadsides.

Canada thistle is a perennial and primarily found in central and northern Illinois. Bull thistle, on the other hand, is found throughout most of Illinois. Unlike most weeds, bull thistle is a biennial plant, completing its life cycle in two years.

  • Weed type: Broadleaf 
  • Life cycle: Perennial or biennial

How to manage thistle:

  • Mechanical control: Regular mowing and hand-pulling can help manage thistles. To prevent regrowth, the entire root system must be removed.
  • Chemical control: Post-emergent herbicides containing 2,4-D or glyphosate can be effective in controlling thistles.

Yellow nutsedge (Cyperus esculentus)

closeup of yellow nutsedge
Homer Edward Price | Wikimedia Commons | CC BY 2.0

Yellow nutsedge is a prevalent perennial weed and the most common weedy sedge in Illinois. You can identify nutsedge by its distinct growth habit, with triangular stems and yellowish-green leaves. Additionally, it produces small, yellow-brown flowers arranged in umbrella-like clusters.

A distinguishing feature of yellow nutsedge is its underground tubers, known as nutlets, which give the plant its name. This weed is hard to control due to its rapid reproduction through these tubers. It is commonly found in gardens, agricultural fields, and wet lawns with poor drainage.

  • Weed type: Sedge
  • Life cycle: Perennial

How to manage yellow nutsedge:

  • Mechanical control: Hand-pulling can be ineffective as it often leaves tubers in the ground, allowing the plant to regrow. However, consistent removal of the plants can reduce its spread.
  • Chemical control: Post-emergent herbicides specifically designed for sedges, such as halosulfuron or sulfentrazone, can be effective in controlling yellow nutsedge.

Weeds by region in Illinois

The types of weeds you encounter in Illinois can vary greatly depending on your location within the state. Knowing the specific challenges of your region can assist you in developing an effective strategy to get rid of lawn weeds.

Common weeds in northern Illinois

In northern Illinois, the cooler climate and fertile soil provide ideal conditions for weeds like:

  • Cat’s ear
  • Common burdock
  • Nightshade
  • Plantain
  • Giant ragweed
  • Canada thistle

Common weeds in central Illinois

Central Illinois frequently suffers from weeds, which typically thrive in the warmer temperatures and diverse soil types of the area. In this region you’ll find:

  • Common burdock
  • Thistle (Canada)
  • Plantain

Common weeds in southern and all of Illinois

Weeds in the Prairie State often grow indiscriminately, causing issues for homeowners across Illinois. This problem is particularly prevalent in southern Illinois, where the warmer, more humid climate provides an optimal environment for weeds to thrive.

The most common weeds in Illinois are:

  • Bindweed
  • Chicory
  • Clover
  • Crabgrass
  • Creeping Charlie
  • Dandelion
  • Lambsquarter
  • Ragweed (common)
  • Shepherd’s purse
  • Spotted spurge
  • Thistle (bull)

Tips for weed control in Illinois

Achieving effective weed control in Illinois lawns involves prevention, consistent maintenance, and effective control methods. Additionally, it involves maintaining a healthy lawn, using mulch, performing regular weed checks, and applying herbicides correctly.

  • Identify the weeds: Identifying the types of weeds in your lawn or garden is the initial step in weed control. Identification aids in selecting the most effective treatment methods.
  • Maintain a healthy lawn: A well-kept, healthy lawn is your best defense against weeds. Following a month-to-month calendar for lawn care in Illinois can keep you on track. Tasks like mowing, watering, and fertilizing help keep your grass healthy and strong, which makes it harder for weeds to take root.
  • Hand-pull: Manual removal is an effective method for controlling small weed infestations. Ensure to remove the entire root system to prevent regrowth.
  • Use herbicides wisely: While herbicides can effectively control weeds, use them sparingly and only as a last resort. Always follow the manufacturer’s instructions when using herbicides.
  • Mulching: Applying mulch to your garden beds can suppress weeds before they invade your lawn by blocking the light they need to grow. It also aids in retaining soil moisture, benefiting your other plants.

FAQ: Weeds in Illinois

How much does weed control cost?

Professional weed control typically costs between $65 and $165, with an average cost of $100 for each treatment. You can spend as little as $35 up to $615 (or more) depending on several factors, but the largest one is the size of the area that needs to be treated.

What types of grass are the most weed-resistant?

The most weed resistant grass seed for Illinois depends on where you live. In northern and central Illinois, the most weed-resistant types of grass include Kentucky bluegrass mixed with perennial ryegrass or tall fescue. For southern Illinois lawns, Zoysiagrass effectively keeps weeds at bay. 

When you choose the best grass types for Illinois, your lawn will crowd out weeds before they can establish in your yard.

Keep in mind that timing is key. The best time to plant grass seed in Illinois to outcompete weeds depends on what type you get. Cool-season grasses, like Kentucky bluegrass or tall fescue, are best planted in early fall, while warm-season grasses, like Zoysia, should be planted in the spring.

How harmful are the weeds in Illinois?

While some weeds in Illinois are harmful, others are beneficial. For example, ragweed pollen is a primary cause of hay fever. Nightshade plants are often poisonous if consumed. On the other hand, dandelions are highly nutritious to eat and beneficial for pollinators.

When to call a pro

When keeping up with the weeds becomes overwhelming or the infestation is too large to manage, it’s time to seek professional help. For expert assistance with weed control in Illinois, consider Lawn Love. We can connect you with local weed control professionals who offer effective, tailored solutions for your lawn’s specific needs.

Main Image Credit: Luke Jones | Flickr | CC BY 2.0

Raven Wisdom

Raven Wisdom is a screenwriter from West Texas and a proud mom of two in an autism family. Self-described as "half-feral but mostly harmless," Raven loves houseplants, a good laugh, and furry friends.