By Pat Kelly Those pretty purple flowers popping up across your lawn are not wildflowers — they are weeds, and they are taking over. Purple weeds are among the most aggressive lawn invaders in North America, spreading through underground rhizomes, creeping stems, and prolific seed production. By the time most homeowners notice the purple blooms, the root systems are already deeply established.
The good news: every common purple-flowering weed is a broadleaf plant, which means a selective herbicide can target them without damaging your grass. This guide covers the four most common purple weeds in lawns, how to identify each one, why they are so difficult to control, and the organic selective method that eliminates them while keeping your turf intact.
Wild Violet — The Waxy Perennial
Scientific name: Viola sororia
Wild violet is one of the most frustrating purple weeds homeowners face. It is a perennial — meaning it comes back year after year from the same root system — and its thick, waxy leaves resist absorption of many conventional herbicides. According to Penn State Extension, wild violet is considered one of the most difficult-to-control broadleaf weeds in residential turf.
How to identify:
- Heart-shaped, glossy, hairless leaves
- Grows in a low rosette pattern close to the ground
- Purple, violet, blue, or white flowers in spring
- Spreads through underground rhizomes
- Thrives in moist, shaded areas but tolerates full sun
What makes wild violet particularly dangerous is its dual reproduction strategy. It spreads through both rhizomes (underground stems) and seeds — including cleistogamous flowers that produce seeds underground without ever opening. This means the plant is spreading even when you cannot see any blooms above ground.
Ground Ivy (Creeping Charlie) — The Aggressive Creeper
Scientific name: Glechoma hederacea
Ground ivy — also known as creeping charlie, gill-over-the-ground, and run-away-robin — is a member of the mint family and one of the most aggressively spreading purple weeds in North American lawns. Purdue Extension identifies it as a primary lawn weed across the Midwest and Northeast.
How to identify:
- Round, scalloped (kidney-shaped) leaves, slightly hairy
- Square stems — a telltale sign of the mint family
- Small purple to blue-purple tubular flowers
- Creeps along the ground, rooting at every node
- Strong minty smell when crushed
Ground ivy's creeping growth habit makes it especially destructive. As the stems spread across the lawn surface, they root at every leaf node — meaning a single plant can create dozens of new rooted colonies in one growing season. Pulling it up is futile because every fragment left behind can regenerate into a new plant.
Henbit — The Square-Stemmed Invader
Scientific name: Lamium amplexicaule
Henbit is a winter annual that germinates in fall, survives through winter, and flowers with pink-purple blooms in early spring. It belongs to the mint family (like ground ivy) and shares the characteristic square stems, but henbit grows upright rather than creeping. It favors thin, bare, or disturbed areas of lawn — the patches where turf is weakest.
How to identify:
- Square stems that grow upright (6 to 12 inches tall)
- Round, deeply veined leaves that clasp the stem
- Pink-purple tubular flowers clustered at the top
- Lower leaves have petioles (stalks); upper leaves do not
- Often confused with purple deadnettle — but henbit leaves are rounder
Henbit vs. Purple Deadnettle — the easy test: Crush the stems. Both have square stems, but henbit leaves are rounder and clasp the stem directly. Purple deadnettle leaves are triangular and the upper leaves turn reddish-purple. Once you spot the difference, you will never confuse them again.
Purple Deadnettle — The Winter Annual
Scientific name: Lamium purpureum
Purple deadnettle is closely related to henbit and shares many characteristics — square stems, mint family membership, winter annual life cycle. But purple deadnettle has a distinctive look: the upper leaves turn reddish-purple, creating a colorful crown that stands out in early spring lawns. Despite the name, it is not related to stinging nettles and does not sting.
How to identify:
- Triangular to heart-shaped leaves with fine hairs
- Upper leaves turn distinctly reddish-purple
- Small pink-purple flowers between the upper leaves
- Square stems, typically 6 to 10 inches tall
- Grows in patches in thin or bare lawn areas
Like henbit, purple deadnettle drops thousands of seeds before dying in summer. The key to long-term control is treating in early spring before flowering — breaking the seed cycle so fewer plants germinate the following fall.
Why Purple Weeds Are So Hard to Kill
Purple-flowering weeds share traits that make them among the most persistent lawn invaders. Understanding these defense mechanisms explains why pulling, mowing, and many herbicides fail.
Waxy Leaf Coating
Wild violet's thick, glossy cuticle repels water-based herbicide sprays. The product beads up and rolls off instead of being absorbed. A dehydration-based herbicide bypasses this barrier by drawing moisture from the tissue rather than needing to penetrate it.
Underground Root Networks
Wild violet spreads through rhizomes. Ground ivy roots at every node. Both weeds have extensive underground systems that regenerate new growth even after the visible plant is removed. Pulling leaves fragments behind that regrow.
Prolific Seed Production
Henbit and purple deadnettle each produce thousands of seeds per plant. Wild violet produces seeds underground. Even after removing the parent plants, the soil seed bank ensures new weeds emerge the following season.
Shade and Moisture Tolerance
Most purple weeds thrive in conditions where grass struggles — shaded areas, moist soil, compacted ground. They fill in wherever turf thins out, then spread into healthy lawn areas from those footholds.
How to Control Purple Weeds Without Killing Grass
The central challenge with purple weeds is that they grow inside your lawn. You cannot spray a non-selective herbicide without killing the surrounding grass — which creates bare patches that invite even more weeds. The only approach that works is selective weed control.
Salacia is the first OMRI-certified selective herbicide. Its Hybrisal Technology works through osmotic dehydration — drawing moisture out of broadleaf weed tissue while narrow grass blades retain enough moisture to recover. This physical mechanism is especially effective against purple weeds because it does not need to penetrate waxy leaf coatings to work. The dehydration process draws water out of the tissue from the surface.
Application Strategy for Purple Weeds
Mow low before treating
Drop your mowing height to expose the weed crowns. Purple weeds grow close to the ground — mowing shorter than usual helps the spray reach the base of the plant where the growth tissue sits.
Spray during active growth
Treat in early spring (March-May) or early fall (September-October). For henbit and purple deadnettle, early spring before flowering is critical to prevent seed set. Temperatures between 60 and 80 degrees Fahrenheit.
Thorough coverage on all weed surfaces
Wet the weed foliage thoroughly to the point of runoff. For ground ivy, follow the creeping stems and treat the entire network — missing one rooted node allows regrowth.
Plan for follow-up on perennials
Wild violet and ground ivy may need a second application one to two weeks after the first to exhaust root energy reserves. Henbit and purple deadnettle (annuals) typically need only one treatment if applied before seed set.
For detailed timing charts and application techniques, see the timing and application guide. For the science behind how selective herbicides differentiate between weeds and grass, read how selective herbicides work.
Ready to Take Back Your Lawn?
Salacia™ is the first OMRI-listed organic herbicide with true selective action — kills weeds, not grass. Choose your lawn size:
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Real results, real lawns — watch Salacia eliminate tough weeds while your grass stays perfectly untouched.
Intelligence
Not Sure About Your Situation? Ask Lanaturo Intelligence.
Snap a photo of your weeds, get an instant species ID, check real-time application conditions for your location, and receive a tailored treatment plan.
Ready to Take Back Your Lawn?
Salacia™ is the first OMRI-listed organic herbicide with true selective action — kills weeds, not grass. Choose your lawn size:
Your Lawn Does Not Need Purple
Wild violet, ground ivy, henbit, purple deadnettle — they look charming until they own your yard. These weeds have evolved defenses that defeat hand-pulling, mowing, and most conventional sprays. But they are all broadleaf plants, and a selective herbicide that works through dehydration treats them as exactly what they are: targets. Your grass stays. The purple goes.
Pet Friendly — everything else second.
This article is for informational purposes. Always follow product label directions for application rates, timing, and use. Salacia is OMRI certified organic and labeled Pet Friendly.
