Weeds with purple flowers are beautiful when in bloom, but they can sometimes be annoying in our gardens. Some of the plants found here can be very attractive but toxic.

Weeds with Purple Flowers

Our list enables homeowners to determine if the weeds found in their gardens can pose any harm. If you’re wondering if the purple flowering weeds are pretty harmless, we’ve got the most common ones listed for you.

List of Weedy Plants with Purple Flowers

1. Ground Ivy

Ground Ivy Groundcover

Plant information
  • Glechoma hederacea – scientific name
  • Lamiaceae – family
  • USDA zone 4 to 13
Distinguishing characteristics
  • Kidney-shaped, toothed, and bright green leaves
  • Funnel-shaped violet flowers in twos and fours
  • Strong smell of blackcurrants
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • Flowers and leaves sometimes look similar to spinach
  • Can be poisonous when consumed in large amounts, especially for horses, wine, and cattle
  • Invasive in many areas due to aggressive growth and spread

Ground ivy, also known as creeping Charlie, belongs to the same family as mint. Since it is herbaceous, it is sometimes added to dishes for its bitter flavor. Others brew parts of the plant, including its purple-colored flowers, as tea due to its high vitamin C content and then the tea is topped up with a sweetener.

However, when they start to grow as weeds, they get pretty aggressive, and they would spread as well, which would be hard to remove if not with herbicides. The condition for their growth would be moist and well-draining soil, as long as the sun is bright and upon it.

2. Wild Violet

Wild Violet Wildflower

Plant information
  • Viola sororia – scientific name
  • Violaceae – family
  • USDA zone 5 to 9
Distinguishing characteristics
  • Low-growing and clumping growth habit with fibrous root systems
  • Heart-shaped leaves with pointed tips and rounded teeth at the margins
  • Has five sepals and petals in shades of violet to purple
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • No known reports of toxicity of the plant
  • Hard to control due to its high resistance to many herbicides
  • They are ones that grow heavily in many areas due to aggressive growth and spread

The wild violet weed produces little flowers that are beneficial insects find attractive. Nectar from each purple flower draws bees, butterflies, and even birds to feed on; through this, they would attract a number of pollinators.

Wild violet plants have antioxidant and anti-inflammatory properties, which have been used in traditional medicines. However, these weeds are ones that have an aggressive characteristic with their growth, and they would spread through their rhizomes.

3. Purple Dead Nettle

Purple Dead Nettle Herb

Plant information
  • Lamium purpureum – scientific name
  • Lamiaceae – family
  • USDA zone 3 to 9
Distinguishing characteristics
  • Low-growing growth habits but can sometimes reach up to 10 inches tall
  • Square stems produce fuzzy leaves and purple tops
  • Flowers are small with colors that range from fuchsia to purple
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • No known reports of toxicity of the plant
  • Plant parts contain astringent, diuretic, diaphoretic, and purgative properties that are often used in traditional medicine
  • Aggressive growth and spread when they establish

This is the weeds that are also known as red dead nettle or purple archangel, this weed with purple flowers is an annual flowering plant usually found in Asia and Europe.

Surprisingly, the purple dead nettle has traditional medicinal uses for chills, cuts, and wounds. However, their spreads are something to consider stopping with the use of herbicides.

4. Black Nightshade

Black Nightshade Herb

Plant information
  • Solanum nigrum – scientific name
  • Solanaceae – family
  • USDA zone 5 to 11
Distinguishing characteristics
  • Rough stems produce leaves that can be slightly hairy to hairless
  • Small star-shaped pale purple flowers come out in clusters in the leaf forks
  • Immature fruits are dull green before turning to a dark purplish-black color
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • The entire plant is considered toxic, especially the immature green berries
  • Parts of the plant contain high amounts of solanine, which can cause nausea, headache, and mild stomach upset
  • Has a strong and an invasive growth and spread

Each purple colored flower of this plant gives way to clusters of dangerous berries, which should not be eaten. While it has non-toxic relatives, such as tomatoes and eggplants, this particular weed presents a health hazard in the presence of curious children and pets.

These weeds are prone to grow when the environment is rich in minerals, and the soil is moist. Also, the sun has to be bright for them to develop and spread as well. To get rid of them, you should check herbicides that have a content of glyphosate, because this is the active ingredient that works to neutralize them.

5. Canada Thistle

Canada Thistle Weed

 

Plant information
  • Cirsium arvense – scientific name
  • Asteraceae – family
  • USDA zone 5 to 10
Distinguishing characteristics
  • Alternate leaves are lance-shaped, irregularly lobed, and have wavy, toothed margins
  • Clustered flowers are usually purple to pink in color. However, occasionally the plant produces white flowers
  • Grows to around two to five feet tall in height
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • The plant produces nitrate, which is toxic to horses when ingested in large amounts
  • Competes and wins over other native, rare, or endemic plants by forming monocultures
  • Has such a strong growth with a developing characteristic

Due to its quick growth, it competes with many local plants, even if its nectar from each purple blossom helps feed bees and butterflies.

If you find this weed, also known as creeping thistle, growing in your garden, use a selective herbicide to prevent its spread, because they are known to grow almost two to five feet tall in their height, and you wouldn’t want them to spread as much.

6. Common Thistle

Common Thistle Weed

Plant information
  • Cirisum vulgare – scientific name
  • Asteraceae – family
  • USDA zone 5 to 10
Distinguishing characteristics
  • Biennial plant with stiff hairs on top and wooly texture on the bottom
  • Fruit is covered in spines with a bright purplish-pink or white flower cluster perched on the terminal shoot
  • Stem is spiny while leaves are densely covered with sharp spines
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • Considered to be mildly toxic to humans only when ingested in large quantities
  • Spines may prick or irritate human skin upon contact
  • Pull them using a lawn mower

Due to their spiny properties, this weed is usually left alone by many animals, allowing it to spread even more. While butterflies and bees enjoy the nectar coming from each purple-colored flower, this weed can be more of an annoyance than a welcome plant.

On another note, you should also remember that only in the right condition and neglect is how these weeds would grow. As a result, if you wish to get rid of them, you should either try to pull them by hand, if they are still very young and soft; however, when they get invasive, you should run on them with a lawn mower.

7. Dovesfoot Geranium

Dovesfoot Geranium Groundcover

Plant information
  • Geranium molle – scientific name
  • Geraniaceae – family
  • USDA zone 6 to 10
Distinguishing characteristics
  • Small weed reaching up from 2 to 11 inches in height
  • Branching growth habit with hairy ascending stems and palmate leaves in a rosette arrangement
  • Flowers are pinkish-purple with jagged petals
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • Used in several folk medicines to cure various ailments, although studies have yet to confirm its efficacy
  • Grows and spreads in an aggressive characteristic

The dovesfoot geranium is a small but quick-growing weed with purple blooms has slowly but steadily crept up from various grasslands and into cultivated areas. While its beneficial properties are still being studied, its growth habit can easily compete with local plant life.

It is known to grow in the USDA zones six to 10, and it would spread quite aggressively, as long as there is moisture in the soil, and full sun. On another note, if you wish to get rid of these weeds, you can use a lawn mower, or you could also use some herbicides as well.

8. Wood Forget-Me-Not

Wood Forget Me Not Wildflower

Plant information
  • Myosotis sylvatica – scientific name
  • Boraginaceae – family
  • USDA zone 3 to 8
Distinguishing characteristics
  • Hairy tufted plant that grows from five to 12 inches in height
  • Oblong and lance-like hairy green leaves are one to three inches long
  • Produces small five-lobed purple flower with white or yellow centers in dense cymes
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • Not toxic
  • Can grow and develop in an aggressive manner

This prolific plant has beautiful purple and tiny flowers, making it one of the more welcome weeds on this list. Additionally, the plant is known for attracting bees, butterflies, moths, and other pollinators due to its pollen-rich flowers.

These are safe if they start to grow and spread, and if kids play around them, you don’t have to worry so much; however, be conscious of the Chinese variety, because those weeds that have purple flowers can grow and become toxic.

9. Henbit Deadnettle

Henbit Deadnettle Weed

Plant information
  • Lamium amplexicaule – scientific name
  • Lamiaceae – family
  • USDA zone 5 to 8
Distinguishing characteristics
  • Leaves of this weed are tinted in purple shades and turn green as they mature
  • Crushed leaves emit a slightly earthy aroma, similar to kale
  • Flowers come in shades of pink to purple and have darker purple spots compared to the purple dead nettle
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • Parts of the plant are sometimes used in teas or cooked in dishes since it is closely related to mint plants
  • Contains high amounts of iron and fiber
  • Spreads fast and invasively

Beloved by hens and visited by hummingbirds, this particular weed has benefits and drawbacks. While it has culinary and therapeutic properties, the henbit deadnettle can easily take over agricultural lands, which means that they are safe, although are fast to spread and develop.

10. Musk Thistle

Musk Thistle Weed

Plant information
  • Carduus nutans – scientific name
  • Asteraceae – family
  • USDA zone 6 to 9
Distinguishing characteristics
  • Stems are usually smooth and hairless
  • Flower heads are in “powder puff” shapes unlike other thistle flower heads
  • Colors of the flower are in shades of deep rose to purple
Growing conditions
  • Moist, well-draining soil
  • Full sun to partial sun
  • Regular watering schedules
Associated issues
  • Not toxic
  • Have a potential to become invasive because of its aggressive growth

Also known as the nodding thistle, this weed with purple tiny flowers competes unfairly with local plants since animals avoid its spines. As a result, it spreads quickly over vast expanses of land and is considered a noxious weed by many farmers, even though it is not a toxic plant to fear any damages it may cause.

Conclusion

While a purple flower might look magical, the plant that produces it is not always beneficial to your garden. Let’s recap what we’ve learned so far:

  • Some weeds can be quite toxic, so it’s best to keep them away from your garden.
  • Other weeds may have medicinal properties but can still be invasive.
  • A purple-colored flower from a thistle can easily cause small pricks and skin irritation upon contact.

A purple bloom might have a personal symbolism for you, but you’ll need to remember that it still came from a weed. Have you found any in your yard? Let us know in the comments below! You can also check our list of 19 ground cover with purple flowers and our list of 14 bushes with purple flowers!

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