How to Kill Creeping Charlie and Wild Violet

Most weeds on a lawn die from the bag you already own. These two do not, and people usually conclude the product was defective or the weeds are simply invincible.

Neither is true. Creeping Charlie and wild violet defeat a standard three-way broadleaf herbicide for two different reasons — and once you know which reason applies, the fix is the same active ingredient and the same month.

Two weeds, two different failures

They get grouped together as “stubborn broadleaf weeds”, which hides the more useful fact: they are stubborn in opposite ways.

Wild violet blocks entry. Penn State’s explanation is that poor control comes from a thick, waxy cuticle that interferes with herbicide uptake and its strong recuperative potential due to robust underground rhizomes. Those rhizomes are described as thick and branching, giving rise to new plants and serving as food storage and overwintering structures. So a spray lands, sits on a glossy surface, and much of it never gets into the plant — and whatever damage does occur is funded back out of an underground reserve.

Creeping Charlie blocks delivery. Here the herbicide gets in. Penn State’s account of poor control is poor or marginal translocation of active ingredients through its extensive stolon network to crown tissues and its strong recuperative potential. Ground ivy runs across the surface on stolons that root at every node, and Iowa State describes it as spreading by seed and by the vining stems which root at their nodes. Each rooted node is effectively an independent plant. Scorch the foliage and you have killed leaves belonging to dozens of crowns that were never reached.

That distinction is why “it grew back” means something different for each. On violet, regrowth comes up from the rhizome in the same spot. On creeping Charlie, the patch refills from nodes at its own edges.

Both share one consequence, and it is the expectation-setting part of this article: Penn State says repeat application over the course of the growing season and over multiple years may be needed for effective control — for both weeds. A single autumn is a start, not a finish.

Telling them apart

They often grow in the same thin, shaded ground, so it is worth being sure which you are treating — not because the chemistry changes, but because the timing and your expectations do.

The minty smell is the fastest field check there is: crush a leaf between your fingers. Iowa State notes ground ivy produces a minty odor when cut or crushed, and violet produces nothing.

Where it grows is a second clue. Iowa State’s note is that ground ivy thrives in damp, shady areas but also grows well in sunny locations — so shade points toward it without ruling anything out. If shade is the underlying issue in that part of the yard, our growing grass in shade guide covers whether grass is even the right answer there.

For sorting any other weed by family first, our weed identification guide has the sixty-second version.

The look-alike that is not a perennial

Henbit gets mistaken for creeping Charlie, and the mistake matters because it changes the entire plan.

Henbit is a winter annual: it germinates in autumn, grows through winter, flowers and seeds in spring, then dies out as heat arrives. Creeping Charlie is a perennial that persists from the same crowns year after year.

The practical test is to do nothing and watch. A patch that disappears on its own by early summer was henbit, and spraying it in May was money spent on a plant that was already leaving. A patch still there in July is creeping Charlie.

Which also means henbit belongs to a different management group entirely — the autumn-germinating winter annuals covered in our Poa annua guide, where a pre-emergent barrier applied before germination is the efficient answer and a post-emergent spray is the expensive one. Our fall lawn care guide places that job in the season.

The active ingredient to buy for

For both weeds on this page, the answer is triclopyr — not the three-way that settles dandelion and clover in one pass.

Penn State on wild violet: herbicides containing triclopyr provide the best control. Penn State on ground ivy: triclopyr alone, fluroxypyr alone, or combinations of triclopyr and fluroxypyr typically provide the best control. Iowa State’s list for ground ivy names triclopyr and 2,4-D as most effective, with MCPP and dicamba as alternatives.

Note what that means about the bag most people already have. A standard three-way product — 2,4-D, MCPP and dicamba — is not useless here, and Iowa State includes 2,4-D among the effective options for ground ivy. But triclopyr is the ingredient the sources reach for first, and it is the one usually missing from the general-purpose bottle. Our best weed killer guide covers matching chemistry to weed across the whole range.

Two triclopyr products here fit these weeds, and which one you buy is decided by your grass rather than by your weed.

Check the label against your grass first. It excludes bahiagrass, bermudagrass, centipedegrass, kikuyugrass and St. Augustinegrass — most Southern lawns. Safe on buffalograss, fescues, Kentucky bluegrass, ryegrass and zoysiagrass — though on buffalograss it is worth asking whether you need it at all, since K-State treats a weedy stand there as a sign of overwatering rather than a spraying job.

We had that second one filed wrong until 2026-08-02, so here is the correction. Its listing sells it as a brush killer for non-crop areas, and we repeated that. Its label — Reg. No. 81927-11-7401 — lists one site: perennial bluegrass, perennial ryegrass and tall fescue, with ground ivy and wild violet both on its weed table. It is an ester rather than an amine salt, which penetrates better and moves more readily as vapour, so the label’s temperature guidance is the part that matters. On any other grass species, it says injury must be tolerable.

One thing the sources rule out: pulling. Iowa State says that in lawns, pulling is often ineffective because rarely are all stem and root pieces removed, and Penn State says hand removal of wild violet is not effective unless rhizomes are excavated from the soil. Interestingly, Iowa State flips that advice for garden beds, where hand pulling and digging is described as the most effective approach given persistence. In turf it simply propagates the problem.

The natural remedies, honestly

Search for a chemical-free answer to creeping charlie and one recipe dominates: borax. It deserves a straight answer, because it is not internet folklore — it started with Iowa State research, and Iowa State is now the source telling you not to use it.

Why it is tempting. Wisconsin explains the mechanism, and it is real: borax contains boron, “which is necessary in very small amounts for plant growth but is toxic in larger doses,” and “Creeping Charlie happens to be extremely sensitive to boron.” So the theory works. A dose that harms creeping charlie more than it harms grass genuinely exists.

Why that is not enough. Iowa State’s own verdict on the research that started it:

“Because the Iowa State study has not been replicated and so many factors influence its level of effectiveness, the use of borax as weed control for creeping Charlie is not recommended.”

They describe a follow-up at Wisconsin “conducted in much the same way” that “did not have the same results,” and name why: “Too many factors seem to influence how borax works in the soil, including soil pH and soil type.” Their line on the margin for error is the one to remember — with boron, “the difference between plant requirements and toxicity problems is very small.”

And the part that makes a mistake permanent. Wisconsin:

“…boron doesn’t break down or dissipate in the soil, so repeated or excessive applications can result in bare areas where no vegetation can grow.”

And the two variables Iowa State names as the reason results were never repeatable — soil pH and soil type — are exactly the two that differ most between one reader and the next. Iowa's are on record: Wind-laid loess over glacial till, deepest along the Missouri River in the Loess Hills — and in town, whatever subsoil the builder spread back after scraping the topsoil off to sell, with pH running Near-neutral to slightly acidic (6.0–7.0). Boron availability moves with both, so a borax measurement someone posted from a different state was calibrated against different ground. There is no dose to copy.

A herbicide that fails costs you a season. Boron that goes on too heavily does not wash out, degrade or expire. That is the difference between a bad afternoon and a strip of ground that grows nothing, and it is why “natural” is a poor guide to whether something is safe to put on soil.

What Wisconsin suggests instead, for someone who wants an alternative to conventional herbicide chemistry:

“Instead of Borax, use an herbicide containing Fe-HEDTA as an alternative to conventional herbicidal control.”

Iron HEDTA is a contact material rather than a systemic one, so expect it to burn top growth and expect regrowth from the stem network below — Wisconsin notes sequential applications are part of using it. It is the honest version of a natural option: weaker than triclopyr, genuinely lower-impact, and not a single-pass fix.

And the option nobody sells. Wisconsin’s other suggestion is to stop fighting for turf where turf keeps losing: grow “the most suitable type of turfgrass for the area (shade tolerant varieties under trees)”, or “consider removing grass and instead grow shade-loving groundcovers or hostas that compete well with weeds.” Creeping charlie thrives in the shade your grass is failing in — growing grass in shade covers where that fight is winnable and where it is not.

Which shade-tolerant grass, in Iowa. Wisconsin's advice is species-specific and your state already has an answer on record: Fine Fescue is the shade and low-input component grown here alongside Kentucky Bluegrass. Overseeding the shaded strip with that rather than with more Kentucky Bluegrass is the difference between re-fighting this every autumn and not. Before reseeding, settle whether the problem is shade or compaction: your state Extension does not run its own lab, so plan a private test rather than assuming a same-week answer.

Why October beats May

Most people spray these weeds in spring, when the purple flowers make them obvious. That is the wrong month, and the reason is worth understanding rather than memorising.

Penn State: herbicide application in the fall following the first frost allows better translocation of active ingredients to crown tissues when compared to spring applications. In autumn the plant is moving sugars down into crowns and rhizomes to overwinter, and a systemic herbicide travels with that flow. In spring the flow runs the other way — up into new growth you are about to mow off.

Iowa State gives the calendar version: fall, late September through early November, is the best time to control ground ivy, and spring applications are not as effective. It also specifies two applications — one in late September or early October, and a second about a month later.

Penn State's trigger — after the first frost — has a local date: in Iowa first frost lands around Late September along the Minnesota line to mid-October in the southern counties, which is where Iowa State's late-September-to-early-November window anchors itself on your calendar. The state's post-emergent window reads: October, and October is most of it — but check the wind and the date against what is happening in the fields, because early-summer growth-regulator drift is a real seasonal risk here and your own spray carries the same way — the fall end of that range is the half these two weeds care about. Work backwards from the frost date: the second of Iowa State's two applications still needs actively growing weeds, so starting in late September beats starting in late October nearly everywhere we cover.

What that means specifically for Iowa. First frost here lands around Late September along the Minnesota line to mid-October in the southern counties, which puts your first application comfortably inside the late-September-to-early-November window and leaves room for the second a month behind it.

Ground ivy is on Iowa's high-risk weed list; wild violet is not, which usually means ivy is the one you are actually fighting and the violet is incidental.

So the programme is:

1. First application after the first frost, once the plant has been signalled to move resources down.
2. Second application about a month later, before the ground freezes.
3. Repeat next autumn. Both Penn State pages say multiple years may be needed.

This is the same principle behind autumn broadleaf treatment generally — our fall lawn care guide covers why perennial weeds are most vulnerable when they are least visible. Creeping Charlie and wild violet are simply the clearest case for it.

Two constraints from elsewhere on this site still apply. Do not spray in summer heat: the temperature limits that make herbicide fail above 90°F are not suspended for stubborn weeds. And if you are also overseeding this autumn, check the label interval before you seed — most broadleaf products require a wait, which is a scheduling conflict our overseeding guide covers.

Your state and these two

Creeping Charlie yes, wild violet no. The local high-risk list carries Creeping charlie (ground ivy) and does not name wild violet, which simplifies the job: you are fighting the translocation problem, not the waxy-cuticle one. Triclopyr and the autumn timing still apply, and so does the expectation of repeating — but you are not also chasing a rhizome bank that funds regrowth from below.

What that changes practically is where you look. Ground ivy advances from the edges of its own mat along stolons, so treat a wide margin beyond the visible patch rather than only the patch. And because Iowa State places it in damp, shady ground, the colony is usually telling you something about the site — thin turf under trees, or a corner that never dries.

The local autumn entry is Treat creeping charlie in October while it is moving sugars down to the roots — read it as the window for this weed too, not just for the dandelions it names. Ground ivy is the one on that list that will still be there next year if the single pass is all you make.

Your actual spray window in Iowa

Penn State's trigger is the first frost, so this is one of the few jobs where the date genuinely comes from your own climate rather than a calendar. Locally: Late September along the Minnesota line to mid-October in the southern counties A single statewide date makes this easier than it is in states that span a frost range: one window, applied everywhere, with the follow-up roughly a month later.

And read it against the local post-emergent guidance: October, and October is most of it — but check the wind and the date against what is happening in the fields, because early-summer growth-regulator drift is a real seasonal risk here and your own spray carries the same way Where the local window lists a spring option alongside the autumn one, treat the autumn half as the real one for these two weeds specifically — the spring slot is for the easier annuals.

Worth setting against what Iowa has you doing in spring: Wait — Iowa's pre-emergent window is mid-April to early May, later than most advice written for the Midwest assumes Read it as the annual-weed programme. It runs on a different clock from the two perennials on this page, which answer to the first frost rather than to spring soil.

One more reason to treat the October pass as the season's main event here: 2 other weeds on Iowa's high-risk list answer to the same broadleaf chemistry — Dandelion, White clover. Those are the easy ones; a standard three-way product handles them, and it is only the two on this page that need triclopyr in the tank. Buying the four-way once therefore clears the whole broadleaf list rather than just the stubborn pair. What it will not touch is Crabgrass or Annual bluegrass (Poa annua) — grassy weeds and sedges need entirely different chemistry, and our identification guide covers why.

One local condition worth checking, because ground ivy in particular favours damp ground: soil here is Wind-laid loess over glacial till, deepest along the Missouri River in the Loess Hills — and in town, whatever subsoil the builder spread back after scraping the topsoil off to sell, draining Moderate — deep loess takes water down readily but slumps and gullies on any slope, and a town lot built on re-spread subsoil drains nothing like the field beside it. Free-draining soil removes some of the damp-ground advantage this weed usually has, so a colony here is more likely to be about shade or thin turf than about wet soil — which makes the canopy the thing to fix alongside spraying.

What has to close the gap in Iowa

Both of these weeds take ground that the grass has already given up, so the second half of the job is whether your turf can take it back. Iowa lawns lean Kentucky Bluegrass, which spreads by runners — so once the colony is killed the lawn closes the space itself, and the herbicide only has to win once.

The feeding that thickens that turf has a local window: Early September and late October — the fall programme carries an Iowa lawn. Getting that right does more against both weeds than a second herbicide pass, because it removes the opening they need — and on a spreading lawn it is the difference between a repair and a permanent thin patch.

The honest summary

Creeping Charlie and wild violet are not invincible. They are simply the two weeds where the default purchase and the default month are both wrong.

Buy for triclopyr rather than for a brand or a weed count on the front of the bottle. Spray after your first frost, not when the flowers make the weeds obvious in spring, because that is when the plant carries the herbicide down into the crowns and rhizomes that actually need to die. Do it twice, about a month apart. And expect to do it again next autumn — both Penn State pages say plainly that multiple years may be needed.

Do not pull them out of turf; you are dividing them. Do improve the density and light in that part of the lawn, understanding what Penn State says about the limit of that: it slows the spread, and it will not suppress an established colony on its own.

And check first that you have a perennial at all. If the patch clears up by itself in early summer, it was henbit, and the right answer was a barrier last autumn rather than a spray this spring.

On brush the ester is the right form instead — brush and woody plant control.