What Kills Creeping Charlie but Not Grass

Creeping Charlie, also called ground ivy, is one of the most stubborn lawn weeds I get called about, and every homeowner asks the same thing: what kills creeping charlie but not grass? The good news is that this weed is a broadleaf, and your turf is not, which opens the door to selective herbicides that wipe out the ivy while leaving the lawn untouched. Understanding what kills creeping charlie but not grass comes down to picking the right active ingredients and, just as importantly, spraying at the right time of year.

Know Your Enemy First

Creeping Charlie (Glechoma hederacea) is a low-growing perennial in the mint family. You can spot it by its scalloped, kidney-shaped leaves, its square stems, and the minty smell it releases when you crush it or mow over it. In spring it throws up small funnel-shaped purple flowers. It spreads by creeping stems called stolons that root at every node, which is why it forms a dense mat that chokes out grass.

Because it roots as it runs, hand-pulling rarely finishes the job. Leave a single rooted node behind and the patch rebuilds within weeks. That rooting habit is the reason chemical control, timed correctly, tends to be the only reliable path on an established infestation.

Why Selective Broadleaf Herbicides Work

The whole trick rests on plant physiology. Selective broadleaf herbicides are growth-regulator chemicals that scramble the way broadleaf plants grow, causing them to twist, curl, and die. Grasses have a different growth structure, with their growing points protected at the base, so they shrug the chemistry off at normal lawn rates. That is precisely why these products can sit on your fescue or bluegrass without harming it while destroying the ivy woven through it.

Triclopyr: The Heavy Hitter

If I could pick only one active ingredient for creeping Charlie, it would be triclopyr. Ground ivy is genuinely tough, and triclopyr is one of the most effective broadleaf actives against it. You will find it sold on its own and blended into premium lawn weed sprays.

Apply triclopyr to actively growing ivy at the label rate, typically around 1 fluid ounce of concentrate per gallon of water covering about 400 square feet, but always defer to your specific product. Adding a nonionic surfactant at roughly 2 teaspoons per gallon helps the spray stick to the waxy leaves. Triclopyr is safe on most established cool-season lawns, but be cautious near ornamental trees and shrubs, whose roots can pick it up.

Three-Way Combos: 2,4-D, Dicamba, and MCPP

The other proven route is a three-way herbicide, a blend of 2,4-D, dicamba, and MCPP (mecoprop). Each active hits broadleaf weeds a little differently, and together they cover a wider range of weeds than any one alone. These are the classic lawn broadleaf weed killers you see on box-store shelves.

• 2,4-D is the backbone broadleaf killer and handles many common weeds.
• Dicamba adds punch against tougher, waxier weeds like ground ivy, but it moves in soil and can be picked up by tree and shrub roots, so keep it away from the dripline of desirable woody plants.
• MCPP (mecoprop) rounds out the mix and improves control of clover and chickweed alongside the ivy.

A three-way product with dicamba is often more effective on creeping Charlie than 2,4-D alone precisely because of that dicamba component. Mix and apply at the label rate, generally in the neighborhood of 1 to 1.5 fluid ounces per gallon per 500 square feet, and add surfactant if the label allows.

The Borax Myth: Please Be Careful

You will find countless internet recipes claiming that borax, the laundry booster, is what kills creeping Charlie but not grass. The theory is that the boron in borax is toxic to ground ivy at doses your lawn can tolerate. I want to be blunt about this, because I have watched it go wrong.

The window between the amount of boron that harms creeping Charlie and the amount that harms your grass and poisons your soil is razor thin. Boron does not break down; it accumulates and stays in the soil. Overapply even slightly and you can create bare, sterile patches where nothing, including grass, will grow for a long time. University turf specialists who tested borax found the results inconsistent at best and often damaging. Skip it and use a labeled selective herbicide that is actually formulated to spare your turf.

Timing Is Everything: Spray in Fall

Here is the single most important thing I can teach you about creeping Charlie. The best time to spray is not spring, when the plant is flowering and looks most obvious. It is fall, from roughly mid-September through the first hard frost.

In autumn, perennials like ground ivy pull sugars and nutrients down into their root systems to store for winter. When you spray during that downward flow, the herbicide rides along and reaches the roots, delivering a far more complete kill. Spray in spring and you often just burn the tops while the roots survive to regrow. Apply your triclopyr or three-way product on a calm day when temperatures sit between 60 and 80 degrees Fahrenheit and no rain is expected for at least 24 hours.

A spring application does have a role as a follow-up or when the plant is small and actively growing, but if you can only spray once, make it a fall application. Plan on two treatments spaced about 3 to 4 weeks apart for a heavy mat.

Give the Grass Every Advantage

Herbicide clears the ivy, but a thin, struggling lawn simply invites it back. Creeping Charlie thrives in shade, damp soil, and compacted, poorly fed turf. Attack those conditions and you close the door behind the spray.

1. Overseed bare spots in early fall so grass fills the gaps before ivy can recolonize.
2. Prune overhanging limbs to let more sun onto shaded areas, since ground ivy loves shade.
3. Mow cool-season grass at 3 to 3.5 inches to shade the soil and crowd out low creepers.
4. Fertilize on a proper schedule and correct drainage in soggy areas.

Putting It All Together

So, what kills creeping Charlie but not grass? A triclopyr-based product or a 2,4-D, dicamba, and MCPP three-way, applied at label rate with a surfactant, in the fall when the plant is moving resources to its roots. Skip the borax gamble entirely. Follow up the next spring on any survivors, thicken your turf so it can defend itself, and within a season or two that minty green mat will be a memory instead of a chore.

Application Tips That Improve Your Kill Rate

The difference between a spray that mostly works and one that truly clears the ivy often comes down to small details of how you apply it. Ground ivy leaves carry a waxy coating that sheds water, which is why a nonionic surfactant matters so much. That spreader-sticker breaks the surface tension and lets the herbicide sit on and soak into the leaf instead of beading up and rolling off. Add it at roughly 2 teaspoons per gallon whenever the product label permits.

Coverage is the next lever. You want to wet the foliage thoroughly to the point of glistening, but not to the point of runoff, because herbicide dripping off the leaves onto the soil is wasted and can reach tree roots. Spray on a calm morning when the ivy is dry, temperatures sit between 60 and 80 degrees Fahrenheit, and no rain is forecast for at least 24 hours, so the chemical has time to move into the plant.

• Do not mow for 2 to 3 days before spraying, so the plant has full leaf area to absorb the herbicide.
• Wait 2 to 3 days after spraying before mowing, giving the chemical time to translocate to the roots.
• Expect the ivy to curl and twist within a week and brown out over 2 to 3 weeks. A second pass 3 to 4 weeks later catches survivors.

When to Call It a Draw and Reset

Sometimes an infestation is so dense and so tangled into a struggling lawn that spot-treating is a losing battle, and it is worth knowing when to change strategy. If ground ivy covers more than roughly half of an area and the grass beneath it is thin and weak, you may get a better long-term result by clearing the whole patch and starting the turf over.

In that case, treat the ivy with a systemic herbicide in fall, wait the label interval, then in early the following fall strip the dead material, till or top-dress with 1 to 2 inches of compost, and reseed with a grass suited to the light. Early fall seeding, with soil temperatures still warm and nights cooling, gives new turf its best possible start and the density it needs to keep creeping Charlie from ever regaining a foothold. A thick, well-fed lawn is, in the end, the most durable answer to the question of what keeps this weed out for good.