14 Weeds with Purple Flowers You Need to Know

2024-05-18
14 Weeds with Purple Flowers You Need to Know

Eye-catching weeds with purple flowers are at home all over the yard. They pop up in landscape beds and vegetable gardens. They ramble in the lawn and creep between the stones in a patio. The first step to sending one of these aggressive garden weeds packing is to identify it. This list includes some of the most common weeds with purple flowers to help you identify your local invader. Each weed summary includes tips for eradication for the specific species and lawn maintenance tips you can use to prevent the weed from spreading.

01 of 14

Wild Violet

Bright-eyed purple flowers rise above the heart-shaped foliage of this spring flowering weed. A clump-forming plant, wild violet (Viola sororia) grows in small patches that expand year after year.

Commonly Found: Wild violet grows in moist, shady sites including lawns and landscape beds. It can become especially prolific in shaded, thin turf grass.

Control Tips: Wild violet is difficult to eradicate. Hand-pulling is rarely effective as every bit of the roots must be removed; plants quickly spring back from tiny bits of root remaining in the soil. Control wild violets in a lawn by increasing the density of the turf grass through fertilization, regular mowing, and selecting a grass that is well-adapted to the conditions of the site.

02 of 14

Ground Ivy

This vigorous perennial weed has long slender stems and kidney-shaped leaves. Also known as creeping Charlie, ground ivy (Glechoma hederacea) produces purple flowers in spring. The aggressive weed gains ground by forming roots along the above-ground stems. In a season or two ground ivy can take over a big swath of ground.

Commonly Found: Ground ivy invades lawns and landscapes, preferring moist, shady sites but it will grow in full sun.

Control Tips: In small areas ground ivy can be controlled by pulling or digging. This is easiest after a soaking rain. Repeated removal is necessary because ground ivy will regrow from the tiniest root left behind in the soil. Herbicides can be effective although some populations of ground ivy are tolerant of popular chemicals. The best defense against ground ivy is a healthy lawn than can out-compete the ground ivy.

03 of 14

Henbit

Blooming in spring, henbit (Lamium amplexicaule) has pinkish-purple flowers on top of unique 4-sided stems that are purplish in color. Rounded leaves encircle the stem of this winter annual. Henbit germinates in fall, survives winter, and then blooms in spring, sets seed, and dies in early summer.

Commonly Found: Henbit is commonly found in areas where little other vegetation is thriving, such as construction sites and roadsides. It becomes aggressive in lawns when the turf grass is struggling to survive.

Control Tips: The best way to discourage the spread of henbit and eventually eliminate it is a vigorous lawn. With proper fertilization and mowing, a well-suited grass species for the growing conditions will out-compete henbit.

04 of 14

Purple Deadnettle

Closely related to henbit, purple deadnettle (Lamium purpureum) has a triangular leaf-shape versus henbit’s more circular shape. Deadnettle has purple tinged foliage whereas henbit’s foliage is consistently green. Deadnettle has 4-sided stems, purple flowers in spring, and a sprawling growth habit.

Commonly Found: Purple deadnettle is mainly found in soil that is disturbed in fall when it germinates. It can invade thin lawns and open flower beds. This winter annual takes root in loose soil and overwinters before blooming, setting seed, and dying in spring.

Control Tips: Hand-pulling, along with good lawn management are the best ways to control purple deadnettle. Hand pull stands of purple deadnettle as soon as it is noticed in landscape beds. Fertilize, water, and properly mow turf grass to create a strong stand that will eventually overtake the purple deadnettle.

05 of 14

Purple Loosestrife

A bold, branching perennial, purple loosestrife (Lythrum salicaria) stands 5 feet tall at maturity. It has spikes of purple flowers in summer and fall. Purple loosestrife was once sold as an ornamental perennial plant but has been identified as an invasive species in most areas and is no longer in commerce.

Commonly Found: Preferring moist to wet growing sites, purple loosestrife is common in low spots, ditches, and wetlands. It is particularly invasive near waterways.

Control Tips: Hand pulling combined with flower removal is generally effective for small stands of this weed with purple flowers. Hand-pull the weeds as soon as they are noticed, being careful to remove the entire root system. If the weeds are in flower, quickly remove the flower stalks to prevent the seed from ripening and making the problem worse. After removing the flowers, hand-pull the plants.

06 of 14

Canada Thistle

This prickly perennial is easy to spot. Its large, toothed foliage is gray-green and covered with spines. Lavender flowers bloom in mid-summer on top of 3- to 5-foot-tall stems. Canada thistle (Cirsium arvense) produces abundant seeds in late summer and fall.

Commonly Found: These weeds with purple flowers grow just about anywhere. They take root in lean or rich soil and in sun or shade.

Control Tips: Canada thistle is nearly impossible to eradicate by digging or pulling. Small root fragments remaining in the soil will regrow. A strong, non-selective herbicide is effective. Limit the spread of Canada thistle by clipping off flower clusters before they mature and set seed.

07 of 14

Common Burdock

Boasting spiny flowers like a thistle along with smooth, green leaves, burdock (Arctium minus) is a unique plant. It often grows 3 to 5 feet tall and the purple gumdrop-shaped flowers debut from mid-summer through fall.

Commonly Found: Burdock is often found in grassy areas and disturbed soil, such as construction sites.

Control Tips: Pull burdock by hand when plants are small. Dig up large plants, being careful to remove all the tough taproot. If you don’t have time to remove the plant promptly, limit spread by removing flowers before they set seed.

08 of 14

Comfrey

Although it has a long history of culinary and medicinal use, comfrey (Symphytum officinale) spreads aggressively and has become weedy in many areas. It grows 1 to 3 feet tall and has oval leaves and nodding purple flowers in summer.

Commonly Found: Comfrey commonly grows in full sun and disturbed, lean soil.

Control Tips: Hand pull young plants and dig up large plants, being careful to remove the entire root system.

09 of 14

Bull Thistle

Bull thistle (Cirsium vulgare) is a biennial weed. It germinates in spring and forms a cluster of leaves the first year of growth. It produces purple flowers and seeds in year two before dying. Very similar to perennial Canada thistle, bull thistle has more finely cut foliage and a pronounced blue-green color versus gray-green Canada thistle.

Commonly Found: Bull thistle thrives in rich, moist soil.

Control Tips: Hand-pulling and hoeing are effective for small plants. Dig up mature plants, removing all parts of the root system. If you don’t have time to remove the plant promptly, limit spread by removing flowers before they set seed.

10 of 14

Chicory

This airy plant with light purple flowers is frequently spotted on the roadside. Perennial chicory (Cichorium intybus) has toothed leaves like those of a dandelion. It blooms from mid-summer through fall and stands 1 to 3 feet tall.

Commonly Found: Chicory grows well in grassy areas and lean, sandy soil.

Control Tips: Hand pulling and hoeing are the best methods for controlling chicory in landscape beds. If a lawn is infested with chicory, improve the density of the turf grass through proper mowing and fertilization and the grass will likely overtake the chicory.

11 of 14

Asiatic Dayflower

Three-petalled, blue to purple flowers dot the stems of Asiatic dayflower (Commelina communis) as it creeps along the ground. This problematic weed in gardens and lawns hugs the ground, evading mower blades and crawling under plant foliage. It blooms June through October.

Commonly Found: Asiatic dayflower grows in consistently moist soil and is frequently found in boggy, low-lying areas.

Control Tips: Hand pull Asiatic dayflower as soon as it is noticed. Dense infestations in lawns are best combatted by increasing the health of the turf so that it will overtake Asiatic dayflower. Improve the soil fertility and mowing practices to promote a healthy lawn.

12 of 14

Speedwell

A low-growing weed with round leave and bluish purple flowers, speedwell is a common lawn weed in many areas. Speedwell’s long stems hug the ground, avoiding mower blades and expanding across large swaths of soil.

Commonly Found: Speedwell grows best in light, sandy soil that has minimal nutrients. It grows in sun or shade.

Control Tips: Hand pulling speedwell when it is young can be effective in small infestations. Be sure to remove all plant parts to prevent it from growing back. Treat large stands of speedwell with a selective broadleaf weed killer when the plant is actively growing. A healthy, dense lawn will naturally eliminate speedwell.

13 of 14

Lespedeza

Also known as Japanese clover, lespedeza (Kummerowia striata) can easily choke out a thin stand of turf grass with its mat-forming, wiry stems. Its pinkish purple flowers appear in late summer. Because lespedeza grows so close to the ground it usually avoids mower blades.

Commonly Found: Lespedeza makes its home in full sun and areas with sandy, lean soil. It grows well on sites where the soil has been disturbed and compacted, such as construction areas and near driveways and roadsides.

Control Tips: Hand pulling is a great way to get rid of lespedeza when it invades landscape beds. Control lespedeza in turf grass by maintaining a healthy lawn. Fertilize adequately because lespedeza grows best in low fertility soil; it struggles to survive in fertile conditions. Mow and water appropriately for the turf species. Finally, use herbicides specially formulated for lespedeza as a last resort.

14 of 14

Heal-All

Heal-all (Prunella vulgaris) is a perennial weed with rosettes of puckered, hairy leaves. In early to mid-summer, it sends up stems with tiny pineapple-shaped, purple flowers. In the right environment, it grows into large colonies of many plants that can eventually out-compete the surrounding turf.

Commonly Found: These weeds with purple flowers thrive in moist, shaded, well fertilized environments.

Control Tips: Hand pull heal-all in landscape beds. When it infests the lawn, the best control is good turf management practices. Don’t overfertilize. Choose a grass species that is well-suited to the growing conditions; the right grass species for the site will be able to out compete heal all.

Related Article

How to Grow and Care for Calathea

How to Grow and Care for Calathea

Learn how to grow calathea indoors successfully. This guide includes essential tips for watering, humidity, light, and fertilizing.
9 Common Houseplants You Might Not Know Are Poisonous

9 Common Houseplants You Might Not Know Are Poisonous

Many favorite houseplants are toxic if ingested, so be extra careful with them, especially around small children and pets.
8 Common Bird Feeder Mistakes You Might Be Making (And How to Fix Them)

8 Common Bird Feeder Mistakes You Might Be Making (And How to Fix Them)

When keeping bird feeders in garden areas, make sure to avoid these bird-feeding mistakes. Instead, keep your winged visitors healthy and happy year-round.
This Front Yard Prairie Garden Requires Almost No Maintenance

This Front Yard Prairie Garden Requires Almost No Maintenance

An Iowa gardener takes cues from nature to create an easy-care wildlife haven filled with colorful native plants.
How to Attract Fireflies to Your Yard for Delightful Evenings

How to Attract Fireflies to Your Yard for Delightful Evenings

Enjoy a natural light show by learning how to attract fireflies to your yard. These enchanting bugs are not only entertaining, but good for your yard.
How to Make a Pallet Potting Bench for Your Gardening Projects

How to Make a Pallet Potting Bench for Your Gardening Projects

Follow our step-by-step guide to make a beautiful and functional pallet potting bench using recycled wood pallets.
Hydrangeas Not Blooming? 7 Reasons Why and How to Fix the Problem

Hydrangeas Not Blooming? 7 Reasons Why and How to Fix the Problem

Hydrangeas not blooming can be a frustrating problem for gardeners. These straightforward tips will promote tons of long-lasting flowers.
Dress Up Your Home with This Foolproof Foundation Garden Plan

Dress Up Your Home with This Foolproof Foundation Garden Plan

Create a welcoming look for your home with this easy-care combination of foundation plantings that will look great around the foundation of your home.
This Extra-Easy Sun-Loving Garden Plan Blooms for Months

This Extra-Easy Sun-Loving Garden Plan Blooms for Months

Try this extra-easy sun-loving garden plan to enjoy tons of color from tough perennials that don't require a lot of maintenance.
How to Plant and Grow Sword Fern

How to Plant and Grow Sword Fern

This guide provides essential tips on how to grow sword fern, a North American native with a big garden presence.
How to Make a Succulent Heart Planter from Concrete

How to Make a Succulent Heart Planter from Concrete

Cement your love of succulents by whipping up this adorable concrete planter that you can hang up.
11 Small Vegetable Garden Ideas for Maximizing Your Homegrown Harvest

11 Small Vegetable Garden Ideas for Maximizing Your Homegrown Harvest

These small vegetable garden ideas will help you make the most of the growing space you have.
Can You Plant Garlic in the Spring? With These Must-Know Tips, You Can

Can You Plant Garlic in the Spring? With These Must-Know Tips, You Can

Even if you missed the fall planting window, here's how you can plant garlic in spring and still get tasty greens and bulbs to eat.
When Should You Aerate Your Lawn to Grow Healthier Grass?

When Should You Aerate Your Lawn to Grow Healthier Grass?

Knowing exactly when you should aerate your lawn will help you revive a struggling lawn without chemicals. Here's how to tell if your lawn needs aerating and how to time it right.
What Is Grass Paint? Plus 6 Tips for Painting Your Lawn

What Is Grass Paint? Plus 6 Tips for Painting Your Lawn

A coat of easy-to-apply grass paint is a quick way to turn a brown lawn green. Get tips for when and how to use grass paint for a lush-looking lawn.
What You Need to Know About Winterizing a Lawn

What You Need to Know About Winterizing a Lawn

Get a jumpstart on a lush, healthy lawn next spring with this guide on winterizing a lawn. Plus, get your lawn mower ready for winter storage.
How to Create Organic Soil for Your Healthiest Garden Ever

How to Create Organic Soil for Your Healthiest Garden Ever

Turn sand, clay, or barren ground into rich, organic garden soil that will sustain plants for years with the right ingredients and these expert tips.
Peach Tree Diseases and Pests

Peach Tree Diseases and Pests

Here's what you need to know about common peach tree diseases and pests and how to fight them.
18 Backyard Landscaping Ideas to Upgrade Your Hangout Spots

18 Backyard Landscaping Ideas to Upgrade Your Hangout Spots

Use plants, hardscaping, and other backyard landscape design elements such as water features, fencing, and arbors to create privacy and beauty.
16 Front Yard Flower Bed Ideas for a Welcoming Entryway

16 Front Yard Flower Bed Ideas for a Welcoming Entryway

These front yard flower bed ideas will add curb appeal and welcome guests to your home through the seasons.