What Is That Purple Flower Weed On Lawn?

Last Updated on May 11, 2026 by Duncan

It’s a familiar sight in spring: you walk out to check on your lawn, and there’s purple. Scattered clusters of small flowers with heart-shaped leaves, or spreading mats of purple-tinged stems. Pretty, in a way — but not what you planted, and not what you want taking over.

Over 17 years of maintaining lawns and gardens, I’ve fought with every purple weed on this list. Some I won quickly. Others took multiple seasons and a proper understanding of how the plant actually works before I made real progress.

This guide covers the four purple-flowering weeds you’re most likely to find on your lawn, how to tell them apart at a glance, and what actually works to control or eliminate them.

Quick Identification Guide

Tip: If the stem is square when you roll it between your fingers, you’re almost certainly dealing with a mint-family weed — creeping Charlie, purple deadnettle, or henbit.

1. Wild Violet (Viola sororia)

Wild violet is one of the most recognisable — and most stubborn — purple weeds in North American lawns.

You’ll identify it by its low-growing, heart-shaped leaves that cup inward, forming a loose funnel shape. The flowers are typically violet-purple (occasionally white or bicoloured) and sit on slender stems above the foliage.

Where does it grow?

Wild violet is a perennial that strongly prefers poorly maintained lawns, particularly shaded, moist areas — under trees, along north-facing fence lines, or anywhere your grass grows thin. Plants typically reach 4–6 inches tall but can grow taller in sheltered spots. They grow in tight clumps and spread in two distinct ways:

• Seeds — formed inside inconspicuous, closed flowers near the soil surface (called cleistogamous flowers). These seeds are dispersed by wind, rainfall, and even ants.
• Rhizomes — underground root-like stems that store water and allow the plant to survive drought, hard winters, and repeated cutting. This is why mowing alone rarely eliminates it.

My experience: The wild violet patch in the shaded corner of my garden took me three years to get under control. My first mistake was thinking more frequent mowing would solve it.

What actually happened was that the plants adapted — they simply grew shorter to stay below the blade and still produced seeds from the ground-level flowers I couldn’t see.

That was a humbling lesson in understanding how a weed actually reproduces before deciding on a control strategy.

How to control wild violet

Create the right conditions for grass

Wild violet thrives where grass can’t. Reduce shade where possible — trim overhanging branches, thin out shrubs — and address soil moisture.

A dense, vigorously growing lawn is your best long-term defence. When grassroots run deep and turf is thick, there simply isn’t room for wild violet to establish.

Increase mowing frequency (with realistic expectations)

Mowing more often reduces seed formation and gradually depletes the plant’s energy reserves.

But be clear-eyed about this: mowing alone rarely eliminates established wild violet. Some plants will adapt by growing lower.

Use it as a management tool, not a cure. When mowing, use sharp mower blades — a clean cut stresses the plant more effectively than a ragged one.

Herbicides

No herbicide is specifically formulated for wild violet, but broad-spectrum herbicides using pyridine chemistry — particularly those containing triclopyr and fluroxypyr — have shown strong results. Key application principles:

• Apply in autumn, when the plant is moving energy down to its roots for winter storage. This carries the herbicide to the taproot rather than just burning off surface growth.
• Spot-treat individual clumps rather than broadcasting across the lawn.
• Expect to repeat treatment over 2–3 seasons for established infestations.

Hand removal

For young plants with shallow roots, hand-pulling works well. Grasp the main stem near the soil and pull firmly and steadily.

For established clumps, use a garden fork: insert it at an angle beneath the crown, loosen the surrounding soil, then lever the root mass up.

Try to get as much of the rhizome as possible — any piece left behind can regenerate. Dispose of removed plants away from the lawn; do not compost them.

Organic control options

• Vinegar (acetic acid): Apply directly to individual wild violet plants on a warm, sunny day. Vinegar is non-selective — it will damage or kill any plant it contacts, so precision matters. Repeated applications are necessary, especially for established plants. White vinegar (5% acidity) is the household option; horticultural vinegar (20–30%) is more effective but requires protective gloves and eyewear.
• Lime: Wild violet strongly prefers acidic soil. Raising soil pH by applying garden lime makes conditions less hospitable for the weed over time. Get a soil test first to determine how much lime is appropriate — over-liming causes its own problems for turf.

2. Creeping Charlie (Glechoma hederacea)

Ask any experienced gardener which weed they’d least like to find in their lawn and creeping Charlie — also called ground ivy, creeping Jenny, or gill on the ground — features high on most lists.

Originally introduced to North America by European settlers as a useful shade groundcover, it has become one of the most persistent lawn weeds across the continent.

You’ll recognise it by its bright green, round to kidney-shaped leaves with scalloped (wavy) edges, produced in opposite pairs on a distinctly square stem.

In spring, small bluish-purple, funnel-shaped flowers bloom along the stems, giving lawns that unmistakeable purple tinge. Crush a leaf and you’ll catch a faint minty smell — it’s a member of the mint family.

Where does it grow?

Creeping Charlie is a perennial that thrives in moist, shaded spots — beneath trees and shrubs, along fence lines, and in any area where grass is struggling.

But don’t underestimate its adaptability: it will colonise sunny lawns too, especially where turf is thin, compacted, or under-fertilised.

It spreads primarily via stolons — surface stems that root at their nodes wherever they touch soil. This is what makes it so aggressive: remove most of it, leave a small piece behind, and it regrows. It’s essentially self-propagating in any direction it can reach.

My experience: Creeping Charlie moved into my garden from a neighbour’s untreated boundary. By the time I noticed, it had covered a roughly 2-square-metre patch under my peach tree. I tried hand-pulling for an entire season.

It came back just as strong each time. The breakthrough came when I shifted to a targeted autumn herbicide application combined with improving the soil compaction in that area — once the grass got stronger, the Charlie lost its foothold.

How to discourage it from establishing

Creeping Charlie’s preferred habitat is a neglected, thin, compacted lawn. The most effective prevention is simply good lawn care:

• Plant a grass variety suited to your climate and light conditions — including shade-tolerant varieties for problem areas.
• Fertilise on schedule to maintain dense, vigorous turf.
• Aerate annually to relieve compaction, which opens up deep root development for grass and removes the low-competition environment Charlie exploits.
• Water deeply and infrequently rather than shallowly and often — deep watering encourages deep grass roots that outcompete shallow-rooted weeds.

Removal methods

Hand-pulling

Only practical for small, recent infestations. After rain (when soil is soft), grasp stems near the soil and follow them back to the root, pulling firmly.

Bag all removed material — don’t compost it, as detached nodes can re-root. For larger infestations, a dethatching tool, power rake, or vertical mower can cut and comb out surface stolons across a wider area.

However, be aware: dethatching can spread node fragments to previously uninfested areas, so rake thoroughly after treatment and reseed any bare patches promptly.

Herbicide control

The most reliable removal method for established infestations. Creeping Charlie is a broadleaf weed but is resistant to many standard broadleaf herbicides.

Look specifically for products containing dicamba salt or triclopyr — check the active ingredient list, not just the marketing name.

Application timing is critical:

• Apply in mid-to-late autumn, after the first frost — at this point, the plant is actively translocating nutrients down to the root system, which carries the herbicide all the way to the root rather than just killing surface growth.
• Apply when temperatures are between 16–27°C (mid-60s to low 80s°F) and no rain is forecast for 24 hours.
• Expect to need 2–3 applications across consecutive seasons for a heavy infestation.

Borax treatment

Borax (sodium tetraborate) is sometimes recommended as an organic alternative because creeping Charlie is highly sensitive to boron. Applied correctly, elevated boron in the soil suppresses and kills the weed.

However, this is not a casual DIY fix. The risks are real:

• Grass and other plants are also sensitive to boron. An incorrect dosage can damage or destroy your entire lawn.
• Boron availability varies with soil type and pH. There is very little margin between an effective dose and a damaging one.
• Boron persists in soil and can continue affecting plant growth long after treatment.

If you want to try borax: conduct a soil test first, work with a lawn care professional who has experience with boron treatments, and treat a small test area before applying broadly. Consider this a last resort, not a starting point.

3. Purple Deadnettle (Lamium purpureum)

Purple deadnettle — sometimes called red deadnettle — is a winter annual in the mint family.

Like all mints, it’s aggressive when it has a foothold, but because it’s an annual (not a perennial), its control strategy is fundamentally different from wild violet or creeping Charlie. Stop seed production and you break its cycle.

You’ll identify it by its triangular leaves with rounded lobes and the distinctly square stem. The upper leaves take on a purple-red hue — especially in cooler weather — which gives the plant its name.

Flowers are small, pinkish-purple, and tubular, appearing from late winter through mid-spring. The “deadnettle” part of its name refers to the fact that, unlike stinging nettle, it won’t sting you.

Its growth cycle — the key to controlling it

Understanding the seasonal pattern of purple deadnettle makes control much more intuitive:

1. Autumn: Seeds germinate after summer’s heat fades. Young seedlings emerge.
2. Winter: Seedlings overwinter — they don’t die back, they just slow down. They’re harder to notice now.
3. Early spring: Growth accelerates rapidly as temperatures rise.
4. Mid-spring (April): Pinkish-purple flowers appear. This is your warning sign — act now, before seeds set.
5. Late spring/early summer: Seeds released. Plant dies back as heat increases.

The single most important rule with purple deadnettle: remove or control it before it flowers. Once seeds are released, you’ve started the clock on next year’s infestation.

My experience: I once let a small patch in a neglected corner go through to seed — just once. The following spring, that corner had three times the coverage. It was a sharp lesson in how quickly seed-bank problems compound.

Now I walk the garden in late February specifically looking for the reddish-purple leaf tips emerging, and I pull them before they’ve had a chance to establish properly.

How to get rid of purple deadnettle

Maintain a thick, healthy lawn

Like all of the weeds on this list, purple deadnettle exploits bare, thin, or compacted areas. Plant appropriate grass varieties in infested zones, fertilise regularly, and keep turf dense. Grass competing for the same resources is the most sustainable long-term defence.

Hand weeding

For small infestations, hand-pulling is highly effective — especially before the plant flowers. Water the area first if soil is dry. Grasp each plant firmly at the base and pull with root intact. Bag all removed material and bin it; don’t compost, as residual seeds may still develop.

Mulching

For areas with chronic long-term infestations, the soil is loaded with seeds ready to germinate each autumn. Mulching after plant removal can interrupt this cycle by blocking the light seeds need to sprout. Options include:

• Organic mulch: Shredded bark, wood chips, or garden compost. Effective and improves soil health. Top up regularly as it thins over time.
• Inorganic mulch: Pebbles or gravel laid over landscape fabric. Longer-lasting but less beneficial to soil biology. Keep fabric edges secured and ensure stems don’t contact the fabric to avoid crown rot in nearby plants.

Herbicides

For large infestations too extensive for hand removal, glyphosate is an effective option. Apply when plants are actively growing — spring in cold climates, spring and autumn in milder zones.

Note that herbicides kill living plants only; they have no effect on seeds in the soil. Follow up herbicide treatment with mulching to manage seedling re-emergence.

4. Henbit (Lamium amplexicaule)

Henbit is purple deadnettle’s close cousin — close enough that even experienced gardeners sometimes confuse the two.

The easiest distinguishing feature: henbit’s upper leaves are stalkless, wrapping directly around the stem, while purple deadnettle’s upper leaves have short stalks.

Both have square stems and small tubular purple-red flowers, and both are winter annuals with nearly identical seasonal patterns.

The name comes from chickens — hens have long been fond of picking at this plant, and it’s still used as poultry forage in some areas.

It’s also one of the earliest nectar sources for bees each spring, which is worth keeping in mind before removing it entirely from areas that don’t affect your main lawn.

Where does it grow?

Henbit strongly prefers moist, shaded soil — under trees and shrubs, in beds, and along hedgerows where grass struggles to grow.

Unlike creeping Charlie, it rarely establishes in thick, healthy turf. If you’re seeing henbit in your lawn, it’s a signal that something about your grass’s health or coverage needs attention in that area.

Its growth cycle

Henbit follows the same winter annual pattern as purple deadnettle:

1. Autumn: Seeds germinate as temperatures cool.
2. Winter: Young seedlings persist through cold periods, going semi-dormant in extreme cold and resuming growth in any mild spell.
3. Spring: Growth surges. Reddish-purple flowers appear in mid-spring.
4. Early summer: Seeds set and plant dies as heat increases.

How to get rid of henbit

Act before flowering

Timing is everything. Attack henbit before it flowers and you prevent seed release, meaning you’re only dealing with this year’s plants — not next year’s bank of seeds. Wait until after flowering and you’ve guaranteed next year’s problem regardless of how well you remove the current plants.

Manual removal

Before flowering, grasp the plant at the base in a smooth, steady upward pull to remove root and all. If the weed has already flowered, skip hand-pulling — you risk shaking seeds off as you work.

Instead, apply a layer of organic or inorganic mulch over the area after removing the plants to prevent seed germination the following autumn.

Herbicide control

Apply a broadleaf herbicide in spring when plants are actively growing. Water in after application to activate the formula and ensure uptake.

As with purple deadnettle, herbicides only affect living plants — not seeds in the soil — so combine with mulching for best results.

Prevention

Eliminate the conditions henbit prefers:

• Thin out or prune overhanging shrubs and trees to improve light penetration and reduce moisture retention.
• Plant shade-tolerant grass varieties in problem areas — once grass fills in, henbit loses its competitive advantage.
• In beds and borders where henbit recurs, permanent mulching or ground cover plants are more sustainable solutions than repeated herbicide applications.

When the Purple Weeds Aren’t All Bad

After spending most of this article on how to eliminate these plants, it’s worth pausing on something I’ve come to appreciate over the years: not every purple weed is an emergency.

Wild violets support native bee populations and several butterfly species, including the great spangled fritillary, whose caterpillars feed exclusively on violet leaves. A controlled patch along a fence line or garden border adds genuine ecological value.

Henbit and purple deadnettle are among the earliest nectar sources available to bees each spring, often blooming before anything else in the garden.

In years when I’ve had a cold snap wipe out early flowers, the henbit patch along my back fence has been doing real work for the local pollinators.

The question to ask yourself before full eradication isn’t just “does this look untidy?” — it’s “is it spreading into areas I care about, and what would I lose by removing it entirely?”

A few violets in a shaded corner and a patch of henbit under a hedgerow may be doing more good than harm. The calculus changes the moment they start creeping into your main turf or garden beds.

Frequently Asked Questions

What is the purple flower weed growing in my lawn?

The most common purple-flowering lawn weeds in North America are wild violet, creeping Charlie, purple deadnettle, and henbit.

The quickest way to tell them apart: if the stem is square when rolled between your fingers, you have a mint-family weed (creeping Charlie, purple deadnettle, or henbit).

If the leaves are heart-shaped and cupped inward, it’s most likely wild violet. See the identification table at the top of this article for a full comparison.

What kills purple weeds in lawns without harming grass?

Selective broadleaf herbicides are the most effective option for killing purple weeds without harming grass.

For wild violet, look for products containing triclopyr or fluroxypyr. For creeping Charlie, choose formulas containing dicamba or triclopyr.

For purple deadnettle and henbit, most broadleaf herbicides are effective. Always read the label to confirm turf compatibility and follow dosage instructions precisely.

Why does creeping Charlie keep coming back?

Creeping Charlie is a perennial that spreads via surface stolons that root at every node. Even small fragments left behind after removal can regenerate a new plant.

Complete eradication typically requires a targeted autumn herbicide application (after first frost), followed by improved lawn density to remove the thin-turf conditions it thrives in. Expect 2–3 seasons of treatment for a heavy infestation.

What is the difference between purple deadnettle and henbit?

Both are winter annuals in the mint family with square stems and purple-red tubular flowers.

The key visual difference is in the upper leaves: purple deadnettle’s upper leaves have short stalks and are distinctly reddish-purple; henbit’s upper leaves are stalkless, wrapping directly around the stem, and are less intensely coloured. Control methods are identical for both.

When is the best time to treat purple weeds in my lawn?

It depends on the weed. For wild violet and creeping Charlie (perennials), autumn — after the first frost — is the most effective application window, because the plants are moving energy to their root systems and herbicide follows the same path.

For purple deadnettle and henbit (winter annuals), spring treatment before flowering is the critical window, as it prevents the current season’s seed release.

Are purple lawn weeds harmful to humans or pets?

Wild violet, purple deadnettle, and henbit are non-toxic to humans and pets. Wild violet leaves and flowers are edible and sometimes used in salads.

Creeping Charlie is mildly toxic to horses in large quantities, and there are reports of it causing problems in cattle; it’s generally considered low risk for dogs and cats but should not be consumed in large amounts.

When in doubt, consult your veterinarian if a pet has eaten significant quantities of any lawn plant.

Final Thoughts

Purple weeds are persistent, but they’re not unbeatable.

The pattern I keep coming back to after years of dealing with them is this: every successful control effort started with understanding the weed — its life cycle, how it spreads, what it needs to survive — before deciding on a method.

Throwing herbicide at a problem you haven’t diagnosed correctly doesn’t save time; it just adds chemicals and delays the real solution.

Start with identification, match your control method to the biology of the specific weed, and invest in the health of your underlying lawn. Strong turf wins most of these battles on its own over time.

Good luck out there.