• by Ron Henry
  • Dec 11, 2023

Which Lawn Weeds Have Purple Flowers?

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Common lawn weeds with purple flowers include:

  • Purple deadnettle (Lamium purpureum)
  • Henbit (Lamium amplexicaule)
  • Ground ivy/creeping Charlie (Glechoma hederacea)
  • Creeping bellflower (Campanula rapunculoides)
  • Musk (Carduus nutans), Canada (Cirsium arvense) and bush thistle (Cirsium vulgare)
  • Wild pansies/violets (Viola tricolor)
  • Purple cudweed (Gnaphalium purpureum)
  • Purple vetch (Vicia benghalensis)
  • Purple nutsedge (Cyperus rotundus).

While some of these weeds are beautiful and majestic, they compete with your lawn turf for nutrients, sunlight, and water. Many spread so aggressively that they smother grass entirely. To combat weeds, mow at the right height, water appropriately, and fertilize wisely for grass health and mulch to prevent weed growth, using selective herbicides for targeted control. Keeping a well-maintained lawn forms a robust strategy for effective weed management.

Read on to learn more about purple-flowered lawn weeds and how to effectively treat specific purple weed infestations.

Identifying Purple-Flowered Lawn Weeds

Purple Deadnettle and Henbit

As the cold season approaches, two notorious members of the mint family often make their presence felt — purple deadnettle (Lamium purpureum) and henbit (Lamium amplexicaule). These winter annuals or biennials exhibit vibrant purple flowers that can catch you by surprise. Found in lawns and disturbed areas, they are relentless in their quest for space. To combat these invaders, consider a pre-emergent herbicide in the fall to disrupt their life cycle before they take root.

Purple Deadnettle (Lamium purpureum)

Purple Deadnettle (Lamium purpureum)

Appearance: Low-growing plant with square stems reaching 12 to 15 inches. Heart-shaped leaves tinged with purple, particularly on the upper side.

Flowers: Distinctive, vibrant purplish-pink to purple flowers in clusters in the upper leaf axils, blooming from early spring to late fall.

Habitat: Commonly found in disturbed areas, lawns, gardens, and along roadsides. Thrives in fertile, well-drained soils.

Life cycle: Winter annual or biennial, germinating in fall, overwintering as a small rosette, and flowering in spring. Produces abundant seeds, contributing to rapid spread.

 

Henbit (Lamium amplexicaule) 

Henbit (Lamium amplexicaule)

Appearance: Similar to purple deadnettle with square stems, opposite, rounded, toothed leaves that clasp the stem (amplexicaul).

Flowers: Produces purplish-pink to purple flowers in whorls in the upper leaf axils, blooming in late winter and early spring.

Habitat: Commonly found in lawns, gardens, and disturbed areas, preferring fertile soils with good drainage.

Life cycle: Winter annual, germinating in fall, overwintering as a rosette, then bolting and flowering in spring. Produces numerous seeds, contributing to establishment and spread.

Control Strategies for Purple Deadnettle and Henbit

Selective pre-emergent herbicides: Apply pre-emergent herbicides in the fall to disrupt the life cycle of seeds, minimizing the chance of infestations.

Selective post-emergent herbicides: Use specialized herbicides designed for broadleaf weed control in lawns. Apply during active weed growth to target purple deadnettle and henbit while preserving grasses.

 

Ground Ivy/Creeping Charlie

Ground Ivy/Creeping Charlie

Also known as Creeping Charlie, ground ivy (Glechoma hederacea) boasts bluish-purple flowers and a low-growing, creeping nature. This perennial weed can be invasive, spreading across lawns and gardens with ease.

Ground Ivy Characteristics

Growth habit: Prostrate growth, forming dense mats close to the ground, spreading through creeping stems (stolons) that root at nodes.

Leaves: Rounded and scalloped, resembling common ivy, often dark green but can turn purple in cooler weather.

Flowers: Small, tubular, bluish-purple flowers in clusters, blooming in spring and attracting bees.

Habitat: Thrives in shaded or partially shaded areas, adaptable to various soil types and moisture conditions, commonly found in lawns, gardens, and wooded areas.

Invasiveness: Highly invasive, spreading rapidly through vegetative growth and seed production. Can outcompete desirable grass species, leading to a decline in overall lawn health.

Control Strategies for Ground Ivy

Selective post-emergent herbicides: Use broadleaf weed control herbicides that selectively target ground ivy while sparing grass. Multiple applications may be required for optimal control.

Fall herbicide application: Apply herbicides in the fall when ground ivy stores energy in its roots for winter. This timing can enhance the effectiveness of herbicide treatments.

Shade reduction: Reduce shade in affected areas by pruning overhanging branches or thinning out trees. Creating a less shaded environment makes it less favorable for ground ivy growth.

 

Creeping Bellflower

Creeping Bellflower

With bell-shaped purple flowers, creeping bellflower (Campanula rapunculoides) may seem charming at first, but its invasive nature can quickly turn it into a menace. Found in gardens and lawns, this perennial weed spreads through rhizomes, making it a persistent adversary. 

Creeping Bellflower Characteristics

Height: Reaches 1 to 3 feet in height, depending on growing conditions.

Stems and leaves: Upright, branching stems with serrated, alternately arranged, heart-shaped or lanceolate leaves.

Flowers: Distinctive bell-shaped flowers with five fused petals, varying from pale lavender to deep purple. Borne in terminal racemes.

Habitat: Adaptable to various soils, thrives in sunny or partially shaded areas. It is found in disturbed areas, gardens, lawns, and along roadsides.

Invasiveness: Highly aggressive and invasive, reproduces through seeds and extensive underground rhizomes. Rapid spread makes control and eradication challenging.

Control Strategies for Creeping Bellflower

Manual removal: Hand-pull or dig out plants and rhizomes for small infestations. Ensure thorough removal of rhizomes to prevent regrowth.

Selective post-emergent herbicides: Use selective herbicides for perennial broadleaf weed control. Apply during active growth, following label instructions for optimal effectiveness.

 

Thistles

With their distinctive spiky appearance, thistles are another group of weeds that can infiltrate lawns. Some species, such as the musk thistle (Carduus nutans), display purple flowers. Thistles are resilient and can quickly take over if left unchecked. Regular monitoring and prompt removal are crucial. Herbicides formulated for thistle control can be a valuable tool in your weed management arsenal.

Thistle Characteristics

Leaves: Thistle leaves are typically alternate, deeply lobed, and often have spines along the margins. The shape and appearance of the leaves can vary between species.

Stems: Thistle stems are often tall and erect, and some species can have a branching structure. The stems may be hairy or have spines.

Flowers: Thistle flowers are typically composite, consisting of disk florets surrounded by bracts forming a spiky structure. The flowers can be shades of purple, pink, or lavender, often attractive to pollinators like bees and butterflies.

Common Thistle Species

Musk Thistle (Carduus nutans)

Musk Thistle (Carduus nutans)

Musk thistle is known for its nodding or drooping flower heads and is considered invasive in some regions. It produces distinctive spiny bracts.

Canada Thistle (Cirsium arvense)

Canada Thistle (Cirsium arvense)

Despite its name, Canada thistle is native to Europe and Asia. It has creeping roots and can form dense colonies, making it challenging to control.

Bull Thistle/Spear Thistle (Cirsium vulgare)

Bull Thistle/Spear Thistle (Cirsium vulgare)

Bull thistle is recognizable by its large, globe-shaped flower heads and spiny bracts. It's found in a variety of habitats and is considered invasive in some areas.

Control Strategies for Thistles

Mechanical control: Hand-pulling or cutting thistles before they produce seeds can effectively manage small infestations. However, wearing protective gloves is recommended due to the spines.

Selective post and pre-emergent herbicides: Selective herbicides designed for broadleaf weed control can manage thistles in larger areas. Herbicide application is often more effective before thistles flower and set seed.

 

Related: How to Get Rid of Weeds — Everything You Need to Know

 

Selfheal (Heal-All)

Selfheal (Heal-All)

Selfheal, scientifically known as Prunella vulgaris, is a low-growing herbaceous perennial plant often considered a weed in lawns and gardens. It is also commonly referred to as heal-all due to its historical use in traditional medicine because of its various healing properties. 

Selfheal Characteristics

Height: Grows to 6 to 12 inches, forming dense ground-level mats.

Leaves: Opposite, lance-shaped, serrated edges, often hairy with a slightly toothed margin.

Flowers: Dense, cylindrical spikes of tubular flowers, commonly purplish-lavender. Blooms late spring to early summer.

Habitat: Versatile, thriving in lawns, meadows, open woodlands, and disturbed areas. Adaptable to various soil types and moisture conditions.

Control Strategies for Selfheal/Heal-All

Cultural practices: As with all of the weeds mentioned here, maintaining a healthy, well-managed lawn through proper mowing, watering, and fertilization can help reduce the establishment and spread of selfheal. Mow the lawn frequently to prevent seed head formation and stop the weed from spreading.

Manual removal: Hand-pulling or digging out the plants can be effective for small infestations. Remove as much of the roots as possible to prevent regrowth.

Selective post-emergent herbicides: Selective herbicides designed for broadleaf weed control can be used to manage selfheal. Herbicide application is often more effective when the plant is actively growing.

 

Slender Speedwell

Slender Speedwell

Slender speedwell (Veronica filiformis) is a low-growing, herbaceous annual weed belonging to the Plantaginaceae family. This weed is known for its slender stems and small, pale blue to violet flowers. It often appears in lawns, gardens, and other cultivated areas, competing with desirable plants for resources. 

Slender Sleepwell Characteristics

Height: Grows close to the ground, with stems ranging from a few inches to about a foot.

Stems and leaves: Thin, branching stems covered in fine hairs. Opposite, oval to lance-shaped leaves with serrated margins.

Flowers: Small, tubular, pale blue to violet flowers with four petals. Clustered along stems, blooming in spring and early summer.

Habitat: Adaptable to various soils, thrives in both sunny and partially shaded areas. Commonly found in lawns, gardens, and disturbed areas. Spreads through seeds, forming dense patches.

Control Strategies for Slender Sleepwell

Remove grass cuttings when mowing the lawn, as slender speedwell can regenerate from fragments of old stems. It can be treated with lawn sand during the early spring, but this will not kill the weed; it will just knock it back a little.

Pre-emergent and post-emergent herbicides: Selective herbicides designed for broadleaf weed control can manage slender speedwell. More than one application will likely be needed for management as the weed is resistant to most weed-killing ingredients.

 

Wild Pansies/Violets

Wild Pansies/Violets

Wild pansies, often called wild violets, are charming flowering plants that can add a touch of color to natural settings. However, in lawns and gardens, they are sometimes considered weeds due to their ability to spread rapidly and compete with turfgrass. The scientific name for wild pansies is Viola tricolor, and they belong to the Violaceae family.

Wild Pansy/Violet Characteristics:

Appearance: Low-growing plants with heart-shaped leaves and distinctive flowers featuring five petals in shades of purple, yellow, and white with a characteristic “face” pattern.

Growth habit: Spreads through seeds and rhizomes, forming dense mats that can outcompete surrounding grasses.

Habitat: Thrives in various environments, including lawns, meadows, open woods, and disturbed areas. Prefers moist, well-drained soil, often found in partially to fully shaded locations.

Competitive nature: Forms dense colonies, low growth habit, competing with desirable turfgrass for sunlight, nutrients, and water.

Perennial growth: Persists for several years as perennial plants, posing a persistent challenge in lawns.

Control Strategies for Wild Pansies/Violets

Selective post-emergent herbicides: Use selective herbicides for broadleaf weed control alongside good lawn care and manual removal. Apply during active plant growth for optimal effectiveness, targeting wild pansies while sparing grasses.

 

Purple Cudweed

Purple Cudweed

Purple cudweed (Gnaphalium purpureum), also known as purple everlasting or purple cudweed gnaphalium, is a low-growing annual weed found in lawns, gardens, and disturbed areas. While some may appreciate its small purple flowers, it is often considered a weed due to its ability to compete with grass and other desirable plants.

Purple Cudweed Characteristics

Appearance: Small, herbaceous plant forming a ground-level rosette with woolly or hairy leaves.

Leaves: Lance-shaped, covered in fine hairs, silvery or grayish appearance. It may have a distinct aromatic scent when crushed.

Flowers: Inconspicuous, purple to pink flowers in clusters at stem ends. Blooms late spring to early summer.

Habitat: Adaptable to various soils, thrives in both sunny and partially shaded areas. Commonly found in lawns, gardens, and disturbed soil.

Competitive nature: Forms dense patches, competing with turfgrass for sunlight, water, and nutrients.

Annual growth: Completes life cycle within one season, but prolific seed production contributes to persistence.

Control Strategies for Purple Cudweed

Selective post and pre-emergent herbicides: Use selective herbicides for broadleaf weed control alongside good lawn care and manual removal. 

 

Purple Vetch

Purple Vetch

Purple vetch (Vicia benghalensis), or Bengal vetch, is a flowering plant belonging to the pea family (Fabaceae). While it is cultivated in some regions as a cover crop for soil improvement, it can also be considered a weed in lawns and gardens due to its aggressive growth habit and ability to spread. 

Purple Vetch Characteristics

Growth form: Vining, leguminous plant with sprawling stems reaching several feet. Can climb or trail along the ground.

Leaves: Compound leaves with lance-shaped leaflets arranged oppositely on the stem, often with tendrils for climbing.

Flowers: Striking purple to violet-colored flowers in clusters featuring a distinctive pea-like appearance.

Habitat: Commonly found in disturbed areas, roadsides, and open fields. Thrives in well-drained soils, capable of fixing nitrogen levels in the soil.

Aggressive growth: Rapid spread through vining and trailing stems, potentially smothering surrounding vegetation, including turfgrass.

Competitive nature: Its ability to climb or trail allows purple vetch to outcompete grasses for sunlight, water, and nutrients.

Control Strategies for Purple Vetch

Mulching: Applying a thick layer of mulch in garden beds can help suppress the growth of purple vetch and prevent its establishment.

Selective post and pre-emergent herbicides: Selective herbicides designed for broadleaf weed control can manage purple vetch in lawns. 

 

Purple Nutsedge/Purple Nutgrass

Purple Nutsedge/Purple Nutgrass

Purple nutsedge (Cyperus rotundus), commonly known as purple nutgrass, is a perennial weed that poses challenges in lawns and gardens. Belonging to the sedge family (Cyperaceae), this tenacious plant thrives in moist or poorly drained soil. Despite its name, it's not a true grass but is often mistaken for one due to its grass-like appearance.

Purple Nutsedge Characteristics

Growth form: Sedge plant with distinctive triangular stems, reaching heights of up to a foot. Often found in wet or poorly drained soil. 

Leaves: Long, narrow leaves arranged in sets of three around the stem, forming a characteristic V-shape. 

Flowers: Small, brownish-purple spikelets that emerge from the tips of the stems. Flowering occurs throughout the growing season. 

Habitat: Thrives in moist, poorly drained soil, often found in lawns, gardens, and areas with excessive moisture. 

Aggressive growth: Rapid reproduction through underground tubers (nutlets) that can lead to dense infestations. Can outcompete desirable turfgrass.

Control Strategies for Purple Nutsedge

Cultural practices: Improve drainage in affected areas, as purple nutsedge thrives in moist soil. Proper irrigation management can help reduce its competitiveness. 

Hand removal: Manual removal of plants and nutlets by hand or using a weeding tool. Ensure removal of the entire plant, including underground tubers. 

Mulching: Apply a thick layer of organic mulch to suppress nutsedge growth. This can be effective in garden beds and landscaped areas. 

Post-emergent herbicides: Selective herbicides designed for nutsedge control can be applied to manage infestations. Follow label instructions carefully for optimal effectiveness. 

Preventive measures: Implement good lawn care practices to maintain a healthy turf, reducing the likelihood of nutsedge establishment. Regular mowing and proper fertilization can help create conditions less favorable for nutsedge growth.

 

Related: What Types of Weeds Look Like Grass?

 

Importance of Proper Lawn Care For Weed Control

Maintaining a healthy and vibrant lawn through proper care is paramount in controlling the proliferation of all weeds, not just those with purple flowers. 

  • Regular mowing at the appropriate height deprives weeds of sunlight, limiting their growth and spread. 
  • Adequate watering ensures the overall health of desirable grasses, creating an environment less favorable for invasive species. 
  • Fertilization provides essential nutrients to the grass, promoting robust growth that can outcompete weeds. 
  • Biostimulants contribute to the well-being of the soil and stimulate vigorous plant growth, establishing a competitive ecosystem that naturally inhibits the growth of weeds.
  • Reducing thatch buildup and aerating the soil enhance water and nutrient absorption, strengthening the lawn's resilience against weed encroachment. 
  • Proactive measures, including pruning overhanging branches to reduce shade, contribute to a well-balanced ecosystem that discourages weed development.
  • Mulching functions as a protective shield, restraining the proliferation of weeds by hindering the penetration of sunlight and establishing conditions unfavorable for weed establishment.
  • Pre-emergent herbicides act as a preventive barrier, inhibiting the germination of weed seeds before they can sprout. Examples include Prodiamine, Dithiopyr, and  Specticle FLO.

 


The battle against purple-flowered weeds requires a holistic approach that begins with comprehensive lawn care. Proper mowing, watering, fertilization, and other cultural practices cannot be overstated in creating an environment where desirable grasses thrive, minimizing the space and resources available to invasive species. As seasons transition and various weeds attempt to establish their presence, a well-maintained lawn is a formidable defense. 

To keep your lawn healthy after weed treatment, check out our non-toxic biostimulants and fertilizers that make lawn care a breeze.

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