Connecticut is home to a variety of weeds that can be found in lawns, gardens, and natural areas. These weeds can be challenging to control and can quickly spread, causing damage to the surrounding vegetation. Proper identification and management of weeds are essential to maintain the health and appearance of your lawn and garden.
Understanding the characteristics and growth habits of common Connecticut weeds can help you develop an effective weed control strategy that works for your specific situation.
From invasive species like Japanese knotweed to common weeds like dandelions and crabgrass, Connecticut gardeners must be vigilant in their weed control efforts.

Table of Contents
Connecticut weeds
Name of weed | Family |
---|---|
Black medic | Legume |
Bull thistle | Asteraceae |
Canada thistle | Asteraceae |
Carpetweed | Molluginaceae |
Chickweed | Caryophyllaceae |
Common burdock | Asteraceae |
Common Chickweed | Caryophyllaceae |
Common dandelion | Asteraceae |
Common groundsel | Asteraceae |
Common lambsquarters | Amaranthaceae |
Common mallow | Malvaceae |
Common purslane | Portulacaceae |
Creeping Charlie | Lamiaceae |
Curly dock | Polygonaceae |
Field bindweed | Convolvulaceae |
Hairy bittercress | Brassicaceae |
Henbit | Lamiaceae |
Japanese knotweed | Polygonaceae |
Mouse-ear chickweed | Caryophyllaceae |
Nutsedge | Cyperaceae |
Spotted spurge | Euphorbiaceae |
White clover | Apiaceae |
Wild violet | Violaceae |
Black medic
This annual weed is easily recognizable by its yellow flowers and clover-like leaves. It grows close to the ground and has a shallow root system, which makes it easy to uproot. However, if not controlled in time, it can spread rapidly.
Black medic is often used as a first line of defense against larger weeds like dandelions, as its deep roots can extract moisture from the soil. This makes it an excellent candidate for pre-emergent control, as eliminating black medic can prevent other weeds from sprouting in the same area.
Type
Annual
Family
Legume
Control
When the soil is moist, manually removing this weed can be very effective as it becomes easier to uproot the plant along with its roots. Hence, performing this task during damp conditions can lead to a more successful outcome. Alternatively, an herbicide can also be applied to control black medic.

Bull thistle
Bull Thistle is a biennial weed that is frequently observed in Kentucky and is a member of the Asteraceae family. It is recognizable by its spiny leaves and violet blooms. This weed can grow up to six feet tall and has a taproot that can extend up to three feet deep. Bull Thistle is commonly found in areas that have been disturbed, such as pastures, roadsides, and fields.
Type
Biennial
Family
Asteraceae
Control
Bull Thistle can be difficult to manage due to its extensive taproot. However, one efficient approach is to manually remove the weed before it produces seeds. This involves gripping the plant’s base and extracting it from the soil, ensuring that the entire root is removed.
Another option is to use a selective herbicide that specifically targets Bull Thistle without harming other plants in the vicinity. It is recommended to apply the herbicide during the plant’s active growth period in either spring or fall.

Canada thistle
Canada thistle is a perennial weed that is widespread in various regions of Canada and the United States. What sets this weed apart from other perennials is its sturdy, upright stems that have sharp spines lining their edges. At the top of each stem, clusters of small, purple flowers grow on spikes. Additionally, this weed has subterranean roots that spread through rhizomes.
Type
Perennial
Family
Asteraceae
Control
The best strategy for managing Canada thistle is to prevent its spread. To reduce the number of plants, it is recommended to remove them early by either pulling or digging them out. In situations where there is a large infestation, herbicides containing 2,4-D can be used to eradicate Canada thistle.
Additionally, mowing the weed before it flowers can prevent it from producing seeds. However, it is important to note that completely eliminating Canada thistle can be challenging, and multiple treatments may be necessary.

Carpetweed
Carpetweed is a weed that grows close to the ground and creates a mat on the surface of the soil. It has smooth, circular stems and green leaves that grow in whorls. The plant produces clusters of small, white flowers that can be seen in the leaf axils. This weed typically grows in sandy soils and thrives in areas with high humidity and ample sunlight. It is commonly found sprouting up in pavement cracks or forming mats on the ground.
Type
Annual
Family
Molluginaceae
Control
For small carpetweed infestations, hoeing or manually pulling the weed is an effective method of removal. However, in cases of larger infestations, herbicides can be used to manage the weed. It is advisable to remove the carpetweed before it reaches the flowering stage.

Common Chickweed
Chickweed is a creeping winter weed that grows in lawns. It germinates in cool temperatures and quickly takes root when its seeds come into contact with soil, allowing it to spread and overtake large areas of gardens or lawns. Chickweed is recognizable by the mats of foliage it creates on the ground, as well as its small white flowers. It thrives in moist environments and can be challenging to manage due to its rapid growth and spreading potential.
Type
Annual
Family
Caryophyllaceae
Control
The most effective way to prevent chickweed from growing in your lawn is to take measures to prevent it from taking root. To prevent this weed from flourishing, it is recommended to avoid overwatering your lawn and to raise the mower blade, particularly during the autumn season.

Common dandelion
Dandelions are a common and invasive broadleaf weed that can quickly take over grass and other plants. They have deep roots that can damage the soil and surrounding plants.
Dandelions are difficult to control due to their widespread seeds and preference for acidic soils. To prevent their growth and spread, it is crucial to take proactive measures like maintaining a healthy lawn or garden and using suitable herbicides when needed.
Type
Perennial
Family
Asteraceae
Control
Hand-pulling is effective in removing dandelions, but the entire plant must be removed. Pre-emergent herbicides may not prevent their growth due to their rapid germination rate.
Post-emergent herbicides are recommended instead. However, it is essential to use them correctly to avoid damaging surrounding plants and the environment. Combining hand-pulling and herbicides can control and prevent dandelion growth.

Common groundsel
Groundsel is a small weed that grows to a maximum height of 22 cm and has an upright growth habit. Its flowers resemble miniature dandelion heads, and it flourishes in dry and shady environments. Groundsel is often found around cabbage, courgette, and parsnip plants. The weed produces numerous seeds that can be easily dispersed by the wind, leading to the rapid spread of the weed and potential damage to an entire garden if not controlled.
Type
Annual
Family
Asteraceae
Control
In the early stages of groundsel growth, hand-weeding or mechanical control can be effective as the weed has a shallow root system. Mechanical control is most effective before the weed’s flowers open, as viable seeds can still be produced even after the groundsel is killed by herbicides or other methods. Another popular physical method of controlling this weed is to apply mulch before seed germination.

Common lambsquarters
Lambsquarters is an annual weed that typically has a low to medium growth habit and small, white flowers. It is commonly found in gardens and lawns, where it can spread quickly if left unchecked. The weed is identifiable by its diamond-shaped leaves that are smooth on the upper surface and whitish underneath, as well as its small greenish-white flowers that grow in clusters.
Type
Annual
Family
Amaranthaceae
Control
To control lambsquarters effectively, selective broadleaf herbicides such as 2,4-D or dicamba (Weed Master) can be used. Physical removal is also an option, but it is crucial to ensure that all parts of the plant, including the roots, are removed.

Common mallow
Mallow, also known as Malva neglecta, is an invasive weed originally from Europe that has spread to North America. It is characterized by small, pink or purple flowers and round, lobed leaves and can grow up to 2 feet tall. Despite being related to ornamental plants like hibiscus and cotton, Mallow is still considered a weed due to its invasive nature and ability to outcompete other plants. It can complete its life cycle in one or two growing seasons, making it a persistent and challenging weed to control.
Type
Annual or biennial
Family
Malvaceae
Control
Mallow is difficult to control due to its high seed production and ability to spread rapidly. To prevent its growth and spread, it is crucial to take proactive measures such as maintaining a healthy lawn or garden and using suitable herbicides when needed.
Herbicides containing glyphosate or 2,4-D can be effective in controlling Mallow, but it is important to use them carefully to avoid harming surrounding plants.

Common purslane
Purslane is a weed that has a mat-like growth habit on the ground and resembles a succulent. It is identifiable by its thick, reddish-purple stems and shiny, paddle-shaped green leaves, as well as its bright yellow, star-shaped flowers that only open for a few hours in the morning sun.
This weed is hardy and can survive in extreme heat and dry climates. It has a reputation for quickly covering the ground and outcompeting native plants, making it a nuisance for gardeners and homeowners looking to maintain a diverse and healthy ecosystem.
Type
Annual
Family
Portulacaceae
Control
Preventing the growth and spread of purslane requires taking proactive measures such as maintaining a healthy lawn or garden and using suitable herbicides when needed.
For small infestations, hand-pulling can be effective, but it is crucial to remove the entire plant to prevent regrowth. By implementing these steps, it is possible to control and prevent the growth of purslane in a lawn or garden.

Creeping Charlie
Creeping Charlie is a perennial broadleaf weed that spreads rapidly and can be challenging to control due to its low-growing habit and vigorous root system. It forms mats of foliage with small, scalloped leaves and pale purple flowers, growing flat along the ground. Creeping Charlie thrives in shady areas but can also grow in full sun conditions if the soil is moist.
Type
Perennial
Family
Lamiaceae
Control
Cultivating the soil and removing existing Creeping Charlie plants before they spread is one of the most effective ways to control this weed. Spot-treating with a post-emergent herbicide can also be useful, but due to its creeping habit, multiple applications may be necessary for the best results.

Curly dock
Curly dock is a tall, upright perennial weed with large, ruffled leaves that can grow up to 4 feet in height. It has long stems with branched seed heads and yellow-green flowers that eventually turn into brown seedpods by summer. This weed thrives in moist soils, areas with poor soil drainage, and even lightly shaded areas of a lawn.
Type
Perennial
Family
Polygonaceae
Control
Regularly mowing curly dock is an effective way to control its growth and prevent it from spreading further by stopping it from going to seed. However, this method should not be used if there are other desirable plants in the lawn, as they may also be damaged by mowing.

Field bindweed
Bindweed is a climbing vine with pretty, lilac-colored, trumpet-shaped flowers that may resemble those of morning glory. However, it can grow uncontrollably and quickly engulf other plants once it wraps around a structure, depriving them of sunlight and choking them. As a result, bindweed is a troublesome weed to manage. It thrives in drier soils, which contributes to its aggressive growth.
Type
Perennial
Family
Convolvulaceae
Control
Controlling bindweed growth requires regular watering of flower beds and gardens since it thrives in dry soil. For extensive infestations, irrigate the area first, then use glyphosate to treat bindweed before planting desirable plants. To prevent regrowth, use pre-emergent herbicides or mulch.

Hairy bittercress
Hairy Bittercress is a small weed that can grow up to 3-5 cm tall and has tiny white flowers. It often goes unnoticed as it hides under larger plants. This weed prefers cool and moist conditions and has a unique seed dispersal method. It launches its seeds with an explosive force, spreading them up to almost a meter away. As a result, if not controlled early, it can rapidly spread throughout the garden.
Type
Annual or biennial
Family
Brassicaceae
Control
Controlling Hairy Bittercress involves removing young plants before they reach the flowering stage by hand-pulling or hoeing. It is crucial to remove the entire plant, including the roots, from the soil surface. After weeding, applying a mulch can help prevent further germination.

Henbit
Henbit is an annual broadleaf weed that grows low to the ground and can quickly dominate areas in lawns with weak turf during the growing season.
It has oval-shaped leaves with serrated edges and produces purple tubular flowers. With a fibrous root system, henbit can grow up to 16 inches tall. Its reddish-purple flowers have dark spots on the lower petals and tend to germinate in early fall or winter.
Type
Annual
Family
Lamiaceae
Control
Controlling Henbit involves using Roundup during the weed’s active growth period, but it should be used carefully. The most effective way to prevent Henbit growth is by maintaining a healthy lawn through regular watering and fertilization. Pre-emergent herbicides can also be used to prevent the germination of new invasive weeds.

Japanese knotweed
Japanese knotweed can be recognized by its reddish-purple shoots and white flowers that emerge from pink buds. It has the unique ability to grow through piping, cables, buildings, and foundations, causing significant property damage. This weed species blooms most prolifically during late summer and early autumn. Once established, Japanese knotweed is extremely difficult to control.
Type
Perennial
Family
Polygonaceae
Control
Managing Japanese knotweed requires professional guidance, and approved herbicides can be used to prevent its spread. Achieving complete control of this weed species can take up to three years of treatment.

Mouse-ear chickweed
Mouse-ear chickweed, also known as Cerastium fontanum, is a common annual weed belonging to the Caryophyllaceae family. It can be found in lawns, gardens, and agricultural fields throughout North America. Mouse-ear chickweed typically grows up to 12 inches tall and has small white flowers that bloom from May to October. This weed prefers moist soil conditions and can quickly spread if not controlled.
Type
Annual
Family
Caryophyllaceae
Control
To control Mouse-ear chickweed, it’s important to remove it before it goes to seed. This can be done by hand-pulling or using a hoe to cut the stem below the soil surface. Mulching can also help suppress growth and prevent seed germination. If chemical control is necessary, herbicides containing dicamba or 2,4-D can be effective.
It’s crucial to follow the label instructions carefully when applying herbicides to prevent damage to surrounding vegetation. Regular lawn maintenance, including proper watering and fertilization, can also help prevent the growth and spread of Mouse-ear chickweed.

Nutsedge
Nutgrass, also known as Nutsedge, is a type of perennial weed that grows in clusters and has bright green leaves with sharp edges. The weed produces yellow flowers that emerge from spikes or “nuts” located at the top of the plant. Nutsedge thrives in moist soil and can spread rapidly throughout lawns. It may initially go unnoticed as its seeds look similar to out-of-season Bermuda grass and thatch.
Type
Perennial
Family
Cyperaceae
Control
To control the growth of Nutsedge, regular maintenance is crucial. Maintaining a healthy lawn with proper mowing and watering schedules is essential. Additionally, post-emergent herbicides can be used to target established weeds like Nutsedge. It’s recommended to apply the herbicide during the early stages of growth and follow up with another application as needed.

Spotted spurge
Spurge is a warm-season weed commonly found in container nurseries, grasslands, pastures, roadsides, and prairies. It produces greenish-white flowers and a milky sap when its leaves or stems are broken. Ground spurge and spotted spurge are two types of spurge that have similar appearances, with prostrate to ascending stems carrying oblong or round leaves. This weed is adaptable to various soil types, making it a common sight in many areas.
Type
Perennial
Family
Euphorbiaceae
Control
Hand-pulling can be effective in removing a small patch of spurge. However, prevention is the best method since controlling this weed can be challenging once it has taken root. Post-emergent herbicides can be used to control spurge invasions in gardens or lawns. It’s crucial to apply the herbicide when the weed is actively growing for maximum effectiveness.

White clover
White clovers are prevalent in Utah, although there are several types of clovers. You can recognize white clovers by their white, puffy blooms and leaves, which generally have a pale white “V” on them. This weed species grows low to the ground and can quickly cover an entire lawn. White clover grows actively during late spring, summer, and autumn, and it thrives in lawns that are nitrogen deficient.
Type
Perennial
Family
Apiaceae
Control
Proper lawn maintenance can prevent the growth and spread of white clover. Applying a pre-emergent herbicide is recommended to control the invasion of white clover and other lawn weeds. To eradicate established weeds, it’s important to use a post-emergent herbicide.

Wild violet
Wild Violets are perennial weeds with heart-shaped leaves and small flowers that can be purple, blue, or white in color. They have a low-growing habit and prefer moist soil conditions, which makes them a common sight in lawns and gardens with poor drainage.
If left unchecked, Wild Violets can quickly spread and take over areas of the lawn or garden, making it crucial to take proactive measures to control their growth.
Type
Annual or Perennial
Family
Violaceae
Control
Controlling Wild Violets can be challenging due to their spreading underground roots. Preventing their growth can be achieved by using a pre-emergent herbicide in early spring or fall. Regular lawn mowing can also help keep the lawn healthy and strong enough to outcompete these weeds. However, removing established Wild Violets can be difficult, and post-emergent herbicides may be necessary to control their growth.
