Weeds with purple flowers are undesirable plants that can be a problem in your lawn or garden. These purple flowering weeds can be aggressive when invading your yard and getting rid of these hardy plants is often a challenge. While beautiful and vibrant, these purple weeds can affect other plants by competing for water, nutrients and sunlight.
You may be tempted to keep these flowered weeds. Although some can have medicinal benefits and culinary uses, most will take over your landscaping and should be removed.
With so many different purple flowers, it can be difficult identifying these weeds in your grass or garden.
To help you, we’ve compiled a list of the most common weeds with purple flowers. From tall to small, explore the types of purple flower weeds to find and remove these pesky plants.
What Are Purple Flower Weeds?
The most common purple flower weeds are the henbit, wild violets, creeping charlie, forget-me-nots, purple dead nettle, black nightshade, creeping thistle, musk thistle and bull thistle. While there are many types, these purple weeds can be hardy and aggressive, growing in your lawn and taking over your garden area. Although attractive, you’ll want to get rid of these flowering weeds before they absorb the water and nutrients from other plants.
Common Weeds with Purple Flowers
Purple Dead Nettle
Purple dead nettle is an annual flowering plant that grows quickly to produce purple, white or pink flowers between spring and summer. Also known as a red dead nettle and purple archangel, this weed is a member of the mint family. Purple dead nettle is living proof that even annoying weeds can have benefits.
It is an excellent early food source for pollinators like bumblebees and honeybees and is especially critical in the UK as a pollen source in March and April when these insects need protein for building their nests. Purple dead nettle is also edible for humans and is commonly used in herbal remedies.
Some amateur gardeners may be tempted to leave purple dead nettle alone. While the fragile flowers and fuzzy, heart-shaped leaves are beautiful to look at, this hardy plant is resistant to cold and insect predation, and can quickly take over an entire lawn.
Henbit is a close cousin of purple dead nettle, and as a result, it shares many of the same qualities. Both weeds thrive in damp areas with ample sunlight, and each is a valuable food source for pollinators.
They are both edible plants that are members of the mint family. While purple dead nettle is described as having a strong, peppery flavor, henbit is typically much milder in flavor. Henbit and purple dead nettle also bear a strong physical resemblance and are often mistaken for one another, but there are some key differences.
Henbit has rounder leaves with scalloped edges, its blossoms are a deeper, darker shade of purple and also grows closer to the ground. Both weeds are also especially tenacious and are best managed by pre-emergent herbicides that target them before they start their spread.
Ground Ivy/Creeping Charlie
Ground ivy is a tenacious purple weed that can grow in your lawn and has been able to survive tough weather and terrains. Also known as creeping charlie, field balm, gill-over-the-ground and catsfoot, this weed can be difficult to get rid of and will compete with other plants for water and nutrients. While people can’t come to a consensus on a single name for this plant, they can agree that it is an aggressively invasive weed that should be avoided at all costs.
Originally introduced to North America in the 19th century as a medicinal plant, ground ivy is still used in herbal treatments today. While it is attractive to pollinators, it can also be toxic to large vertebrates like horses who can become very sick if they consume large quantities while grazing. Ground ivy can also devastate native plants by hogging resources like water and nutrients and crowding them out.
Don’t be charmed even momentarily by the lovely lavender tubular blooms that bedeck ground ivy. Once this weed gets a foothold, it is incredibly difficult to eliminate. Unless every root and fragment is removed, it will continue coming back.
Wild violets are beautiful weeds with purple flowers that grow quickly, can take over your yard and are often a challenge to deal with. With heart-shaped petals, these distinctively-hued flowers first start to bloom in early spring and you may be excited by the pops of purple that pepper your lawn. As the warmer summer months arrive, these pretty perennials can proliferate wildly out of control.
There are several reasons why wild violets are so challenging to weed out. Below the soil, thick clumps of stems called rhizomes are difficult to fully remove, as they can put down new shoots when you pull them manually if you aren’t thorough enough. Above the ground, their slick leaves have a waxy coating that makes them impervious to many herbicides.
Many people know forget-me-nots as sky blue flowers with cheerful yellow centers, but these dainty five-petaled blossoms also come in shades of pale pink and pastel purple. While people typically go out of their way to banish weeds from their yards, many gardeners will intentionally include forget-me-nots into their landscaping for a variety of reasons.
First and foremost, with their clusters of delicate flowers, forget-me-nots are a charming visual addition to a garden. From a more practical standpoint, they’re easy to care for and can keep away critters like rabbits and deer that might otherwise graze in their garden.
But while they certainly have both functional and aesthetic advantages, forget-me-nots have their drawbacks as well. If you don’t pay attention to them, forget-me-nots will quickly grow out of control, spreading across your lawn and garden and taking resources from other plants.
The black nightshade is a summer annual plant that withers and dies in the fall when the air gets chilly. While several different plants are commonly referred to as black nightshade, the most prevalent is solanum nigrum or European black nightshade.
Despite its name, European black nightshade can be found throughout North and South America and in South Africa, Australia and its surrounding islands.
While the flowers on this weed are typically white, the stems have a purple tint, particularly when the weather grows colder. It is also studded with berries that progress from green to a deep purplish black.
People are often concerned that black nightshade is as dangerous as the closely-related deadly nightshade. Though the berries can be toxic when ingested, it’s far less poisonous than its frequently fatal relative.
Black nightshade can be hazardous to other plants. This leafy weed can grow as high as four feet tall, preventing smaller plants from getting the sunlight they need to survive.
Canada thistle (also known as creeping thistle and field thistle) is a surprisingly striking weed to look at. This herbaceous plant can grow anywhere between two and five feet in height, and its slender stems are topped by spiky, pom-pom-shaped purple flowers that look like little bursts of fireworks. In mid-July, these flowers will change into white, fluffy seedheads that closely resemble a dandelion.
It’s hard to believe such a picturesque plant could be considered a noxious weed, but it has been declared as one in multiple states. Noxious weeds are the name for certain plants that an agricultural or governing authority has classified as especially harmful to the environment. Those pretty puffballs that emerge each summer are a devastatingly accurate seed dispersal system.
In the course of their life, these pernicious perennials can produce millions of seeds. Canada thistle also has an aggressive root system, giving it a stranglehold on your lawn and making this weed a challenge to remove.
Because Canada thistle spreads so quickly it displaces native plants and destabilizes the local ecosystem. This ripple effect from this also affects native wildlife. This weed also drains moisture and nutrients from the soil which can damage crops for years to come, and even cause long-term erosion.
Like its Canadian cousin, musk thistle is a sight to behold. This larger-than-life biennial plant can grow up to six feet in height and boasts 2-3 inch flower heads as well as leaves that can span as long as fifteen inches. Musk thistle is also known as nodding thistle because its amaranthine flowers are so large that they tend to droop down under their own weight.
Musk thistle shares many characteristics with Canadian thistle beyond their spiny purple blooms. Both are designated as noxious weeds and invasive species in regions all around the globe. However, while Canadian thistle flourishes in low-fertility soil, musk thistle is more bountiful in areas where soil fertility is good.
The common thistle is a ubiquitous weed that can be found lining roadsides in various states and countries in the summer. This thistle goes by several names and each is telling of its characteristics. The moniker spear thistle describes its silhouette of thick, straight stalks terminating in a spiny ball capped in fluffy purple blooms. The name bull thistle alludes to its stubborn tenacity because, once it takes root, it is exceptionally difficult to dislodge.
Common thistle does have some advantages, principally in the field of holistic medicine where it is used to treat nausea and joint pain. In parts of Italy, dried thistle flowers are used as part of the process of making goat cheese. This plant is also appealing to pollinators, including several species of butterflies. But for serious gardeners, the benefits of common thistle don’t outweigh its destructive nature.
Plants can thrive in various environments, and weeds are no exception. The elaborately-named dove’s-foot crane’s-bill happens to prosper in dry soil and arid grasslands. With its rounded, fuzzy leaves, and its pinkish-purple flowers, this low-growing wildflower has a highly-ornamental quality that many people find alluring.
Dove’s-foot crane’s-bill is unusual in that it tends to pop up in bare patches on dry or poorly cared-for lawns. In this respect, it can improve the look of your lawn. With explosive pods that can disperse seeds far and wide, this flower can easily take over your neighbor’s lawn as well. Removing these weeds can help keep peace and harmony in your neighborhood.
Plants have been used for medicinal purposes for tens of thousands of years. As its name implies, selfheal (also known as self-heal, heal-all, all-heal, and heart–of-the-earth) has long been renowned for its healing properties. In medieval times, varieties of selfheal were named after the belief that they could cure virtually any ailment. This member of the mint family is still used in Chinese medicine to treat everything from dry eyes to dizziness to edema.
The indigenous people who originally settled in the United States have also historically made great use of this weed. The Blackfoot, Cherokee, Cree, and Iroquois tribes (among many others) put it to use to treat a variety of ailments. Selfheal was used to treat sore throats, burns, wounds, gastrointestinal distress, fevers, respiratory problems, and a host of other issues.
As helpful as selfheal may be for countless illnesses, it doesn’t contribute to the health of your yard and garden, even restricting grass from growing. Unless you’re planning to create your own herbal remedies, it’s best to kill this wild purple weed in your garden.
How To Get Rid of Purple Flower Weeds In Your Lawn
Herbicides and Chemicals
Herbicides and chemical weed killers are commonly regarded as the most efficient and effective options for eradicating widespread weeds. These substances work in a few different ways.
Some cause a toxic substance to build up at low levels that are just enough to damage plants by destroying them at the root system. Others work by blocking photosynthesis and protein production.
While some products are most successful on weeds that have already grown, others can be applied before weeds even emerge as more of a preventative measure.
Because weed killers and herbicides can vary so much in their function, paying attention to their opponents is essential. Chemical formulations containing glyphosate may kill plants indiscriminately instead of targeting just weeds. Look for newer, more sophisticated products that are designed to be more selective.
Pulling The Weeds
For yards that contain fewer weeds, pulling them up by hand is typically the best solution. Not only is this option environmentally friendly, but it is also cost-effective.
You will need to purchase a few supplies upfront like gardening gloves and a weed-pulling tool, but you’ll get plenty of use out of them in future weeding sessions.
It’s much easier to pull weeds when the soil around them is wet. You can remove weeds after a rainstorm, or just use a hose to dampen the soil around them.
For substantially stubborn weeds, you can break up the soil further by using a handheld pronged garden cultivator or other tools. Then, simply pull the weed firmly out of the ground, removing as much of the root system as you can to prevent future regrowth.
The term mulch is used to describe a wide variety of ground coverings that can be spread across a soil surface. While many people use mulch for purely aesthetic reasons, it also serves many practical purposes.
In addition to improving fertility and conserving soil moisture, mulch suppresses the growth of weeds.
Mulch comes in both organic and inorganic varieties. Synthetic mulch tends to be the best at controlling weed growth but doesn’t have any of the other benefits like soil enrichment.
If blocking weeds from growing is your priority, look for a sturdier organic mulch like wood chips.
Cultural Controls and Lawn Health
There’s an old saying in medicine that goes “an ounce of prevention is worth a pound of cure.” This maxim holds equally true when it comes to caring for your lawn. Keeping your yard at peak health is the best way to prevent weeds from growing in the first place.
Fertilizing your lawn and keeping it well-watered encourages grass to grow thickly, which leaves less room for weeds to pop up. Placing plants close together in your garden can also prevent weed encroachment.
Another simple way to prevent weeds is to select more desirable plants that compete with them. Ground coverings like creeping phlox and wooly thyme grow densely to crowd out weeds that may try to invade.
What Are The Tall Weeds with Purple Flowers Called?
The tall weeds with purple flowers are called mullein and henbit. These tall purple flowering weeds can look beautiful with a vibrant color but can grow quickly across your lawn and garden. You’ll want to kill these weeds to protect surrounding plants and areas.