Wisconsin Weeds – 13 Most Common

Weeds not only ruin the look of a lawn, but also compete with desirable plants for space, nutrients, and sunlight. A thorough understanding of broadleaf weeds is the only way to effectively maintain control over them. Wisconsin is no stranger to weeds. As a homeowner in Wisconsin, you may be able to identify a few weeds. However, there are several weeds you may not know about. This article gives you accurate information on the 13 most common Wisconsin weeds, and how to get rid of them effectively.

spreads rapidly

Table of Contents

Wisconsin Weeds

Name of Weed Family
Creeping Charlie Lamiaceae
Broadleaf plantain Plantaginaceae
Poa Annua Poaceae
Crabgrass Poaceae
Clover Fabiaceae
Purslane Portuculaceae
Shepherd’s purse Brassicaceae
Bur cucumber Cucurbitaceae
Horseweed Asteraceae
Cocklebur Asteraceae
Burdock Asteraceae
Bull thistle Asteraceae
Horse nettle Solanaceae

Creeping Charlie

Also known as ground ivy, the weed gets its name from the creeping stems that sprawl along the ground. The weed can be recognised by its green vine, round leaves, and purple flowers. Creeping Charlie is a low-growing weed that forms a mat-like cover. The weed species thrives in moist areas such as hedgerows, waste areas, woodland margins, and shady locations. It can also survive in sunny locations.

Type

Perennial

Family

Lamiaceae

Control

Creeping Charlie grows well on an unhealthy lawn. Therefore, maintaining a healthy lawn is the best defence. Once the weed takes root and invades your lawn, it’s not easy to eradicate it. Most broadleaf herbicides don’t work well to remove these weed plants. Hand-pulling can be done to remove just one or two weeds. However, when there is a large patch, use a professional-grade herbicide in the autumn season.

creeping roots

Broadleaf plantain

Broadleaf plantain is an aggressive, stubborn weed that takes over neglected lawns, and especially occupies moist areas with little sun. The weed has green, oval-shaped leaves, which form flat rosettes. Its root system is shallow and thick and is up to 18 inches long. The weed species thrive in compacted soil in disturbed areas like agricultural lands and open fields, and along sidewalks, roadsides, and trails. It can survive in both full sun and partial shade.

Type

Perennial

Family

Plantaginaceae

Control

As the plantain grows well in compacted soil, aerating the lawn in the autumn will keep the weed at bay. You must mow the lawn high, at about 3-4 inches, and seed any sparse areas. Despite these prevention measures, if the weed shows up, use a broadleaf herbicide to get rid of it.

Plantain

Poa Annua

Poa annua is a common grassy lawn weed. It resembles Kentucky bluegrass, but its green shade is even lighter. The weed germinates in late summer or early autumn. It is active all through the autumn and flowers the following spring. Poa annua develops a seed head early in the season, which often dies off in the summer due to hot weather. However, it leaves behind ugly bare spots all over the lawn.

The weed species grows well in both full sun and partial shade. It thrives in disturbed soils, and hence you can find it in gardens, lawns, roadsides, waste places, and trail edges.

Type

Annual

Family

Poaceae

Control

The most effective way to control Poa annua is to spray a non-selective herbicide on it multiple times when it is actively growing. These areas should then be renovated. Despite these efforts, the weed may show up, because its seeds may lie dormant in the soil.

Poa Annua

Crabgrass

Crabgrass is the most common weed you can find in Wisconsin. The leaves of crabgrass appear broader than grass blades. They grow in clumps much closer to the ground. Its stems grow outward and look like crabs’ legs. A single crabgrass plant can produce up to 150,000 seeds.

 

Once the weed takes root, it is very difficult to control. Crabgrass is really a pain for lawn owners.

Type

Annual

Family

Poaceae

Control

The key to keeping crabgrass under control is preventing its stubborn seeds from turning into more seed-producing plants. Pre-emergent herbicide applications are crucial, as they target the seeds before they take root. Spot treatment using appropriate herbicides is also recommended and known to be effective in defending against these invaders.

prefer warm soil

Clover

Clovers are short-lived herbaceous weeds. Its compound leaves are alternately arranged on a long stem and have three-toothed leaflets. It can be identified by its delicate, round-shaped, pink or white flowers that are fragrant. They crowd to form dense spikes that could be pink, red, white, or yellow. Clover has small, dry fruits that normally contain one or two seeds.

The weed species produces its own nitrogen, which means it can thrive in undernourished lawns.

Type

Annual or Perennial

Family

Fabiaceae

Control

A thick and healthy lawn that is not mowed too short will generally crowd out the clover. Frequent fertiliser applications also help keep weeds away from your lawn.

indigenous weed species

Purslane

Purslanes resemble baby jade plants. Its stems grow flat on the ground, radiating to form large mats of leaves. The weed has fleshy, succulent leaves with yellow flowers.

The weed species prefers highly disturbed areas and is commonly found in croplands, rocky bluffs, barnyards, nursery plots, cracks in pavements and sidewalks, and waste areas with infertile soil.

Type

Annual

Family

Portuculaceae

Control

Hand-pulling is the simplest method to remove purslane from your lawn if the infestation is small. A single native plant tends to cover a large space in your lawn, so you can easily clear the weed by pulling out its root. Applying a pre-emergent herbicide is also an effective control measure, however, it should be done before the growing season.

Soil solarization is another method to kill purslane and its seed. It is the practice of covering the moist soil with a plastic sheet for four to six weeks in the summer. The procedure should be performed before desirable plants are planted in the garden. 

Purslane

Shepherd’s purse

Shepherd’s purse is a weed characterised by many stems and triangular or heart-shaped seed pods. It has many tiny, four-petaled flowers on the upper part of the stems and branches. The weed species can be found in disturbed areas, roadsides, gardens, trails, and old homesites across Wisconsin. It reproduces by dispersing seeds via water, wind, animals, and vehicle tyres.

Type

Annual

Family

Brassicaceae

Control

The primary means of controlling shepherd’s purse on a lawn is by hand pulling or using a suitable weeding tool. This is the best option if the infestation is in its beginning stages. However, to remove established weeds, using a contact weed killer in early spring before the flowering period is recommended.

weed finds natural resources to thrive

Bur cucumber

Bur cucumber is a non-woody vine with sticky hairy stems and sharply lobed green tendrils. It has clusters of prickly, oval, green fruits and five-lobed, cream-coloured flowers. You can find these weed species growing in low, moist soils. It is capable of spreading across an area of 20 feet wide, as it covers the ground and adjacent shrubs.

Type

Annual Vine

Family

Cucurbitaceae

Control

Hand-pulling or mowing the weed the moment it is found is the best way to keep bur cucumber in check. Post-emergent herbicide applications are known to control the weed effectively. Experts recommend using herbicides containing Dicamba as the active ingredient for controlling the growth and spread of bur cucumber.

early fall

Horseweed

Horseweed is a pesky weed that can reach heights of over 6 feet. Its leaves are alternate, dark green, hairy, and are found crowding the stem. As the stem ascends, the size of the leaves seems smaller. At the end of the stems, it has a dense inflorescence with tiny white rays and yellowish disc florets.

When the sun shines on the horseweed plant, the shadow it casts looks like the tail of a horse; that’s how the plant got its name. The weed species thrive in areas of disturbed soil including orchards and field nurseries, as well as unmanaged areas such as ditches and roadsides. Its seeds are primarily dispersed by wind. 

Type

Annual

Family

Asteraceae

Control

Control attempts are effective when the weed is less than two inches tall. A horseweed plant that reaches above five inches tall can survive most herbicide applications. Herbicides should be applied in early spring – the rosette stage, to prevent seed production. A herbicide mixture of 2,4-D ester or dicamba and glyphosate is largely used to control horseweed invasion in some fields.

Horseweed

Cocklebur

Cocklebur is a tap-rooted weed that normally grows to about 4 feet tall. It can be identified by its single, stout, green stem that is often speckled with purple, finely grooved, hairy side branches. The weed species can be found in waste places, on low ground, and along roadsides. Cocklebur is self-compatible, reproduces from seed, and is wind pollinated.

Type

Annual

Family

Asteraceae

Control

An effective way to control cockleburs is to mow or disc them during the flowering stage. As resprouting may take place after mowing, secondary treatment is often necessary. Sometimes, cut-off plants with immature burs can develop viable seeds.

Applying a pre-emergent herbicide in the spring before the weed comes up is recommended. Herbicides should be used appropriately by following the directions on the label.

life cycle of Cocklebur

Burdock

Burdock is a large plant with spiky purple flowers. Its stem is subtle, striped and whitish pink with big, broad leaves. It blooms during the spring season. In the autumn, the flowers become burred seed pods that often stick to surfaces they come into contact with. The weed species can be found along roadsides, old fields, ditch banks, and waste and neglected areas. Burdock affects the development of native plants by causing root rot and hosting powdery mildew.

Type

Perennial

Family

Asteraceae

Control

To kill burdock, cut the root just below the soil surface, and then you can hand-pull the plant, extracting a large part of the tap root. A dandelion digging tool can be used to remove small plants.

Using a broadleaf herbicide when the plant still remains in the rosette stage is known to effectively kill the burdock plant.

Burdock

Bull thistle

The bull thistle, true to its name, features notable spines, and it can grow up to 6 feet tall. Its foliage has stiff hairs on the upper side and a woolly appearance on the underside. The weeds have spines along the stems and leaves. The flower heads are gumdrop-shaped and contain hundreds of small, purple flowers. The weed species prefers sunny, open areas, but it can tolerate a range of conditions. It is generally found in disturbed areas including trails, roadsides, logged areas, vacant land, cultivated land, and pastures.

Type

Biennial

Family

Asteraceae

Control

The weed can be easily dug up using a shovel. It is recommended to remove the top two inches of the root to kill the plant, particularly after the stems are produced. Bull thistle can be effectively controlled using herbicides containing glyphosate. However, glyphosate will also kill the other grasses. So, experts suggest combining glyphosate treatment with effective re-vegetation of the entire site to prevent re-infestation of the area by seedlings.

noxious weeds bull thistle

Horse nettle

Horse nettle is a herbaceous, broadleaf weed with a stem that grows up to 3 feet tall. Its stems and leaves have hard, thorn-like spines. The flowers are purple to white in colour. The plants begin to bloom about 30 days after emergence. In late autumn, its yellow-orange berry fruits ripen, and each fruit bears 40-170 seeds. The weed species can be found growing on roadsides, pastures, and railroad margins, as well as in waste grounds and disturbed areas.

Type

Perennial

Family

Solanaceae

Control

The only way to organically control horse nettle is by frequent mowing. After the plant flowers, its roots become weak, so allow the plant to flower before mowing the first time. Later, continue to mow regularly to further weaken the plant’s roots. It can take about two years or more to eradicate these weed plants this way.

Well, to speed things along, systemic herbicides can be applied after mowing. Use a herbicide that is labeled for use against horse nettle in the late summer or autumn. Read the instructions carefully before applying to successfully kill the weed. Timely application of the appropriate herbicide is crucial to getting rid of horse nettle.

Horse nettle
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Oliver Wright
Oliver Wright

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