How to Get Rid of Creeping Charlie With Borax

Borax can kill Creeping Charlie, but the dose required to do the job almost always damages the surrounding lawn as well. Research comparing boron-based products for ground ivy control found that while a single fall application reduced ground ivy cover by 77% or more at higher rates, every boron treatment also caused unacceptable injury to Kentucky bluegrass turf. That trade-off is the central problem with this widely shared home remedy, and understanding it will help you decide whether borax is worth trying or whether a different approach makes more sense for your yard.

Why Borax Works Against Creeping Charlie

Creeping Charlie (ground ivy, Glechoma hederacea) is a broadleaf plant, and broadleaf plants are substantially more sensitive to excess boron than grasses. Ecotoxicity testing has confirmed this pattern: dicotyledonous species (broadleaf plants like Creeping Charlie) are far more sensitive to boric acid than monocotyledonous species (grasses).¹ That sensitivity gap is the entire basis for using borax as a selective weed killer. You are exploiting the fact that Creeping Charlie will be poisoned by a boron concentration that your grass can (in theory) tolerate.

Boron is actually an essential micronutrient for all plants, but it has an extremely narrow range between the amount a plant needs and the amount that becomes toxic.² At healthy levels, boron helps build and maintain cell walls. When levels climb too high, the symptoms pile up fast: reduced root and shoot growth, yellowing and browning of leaves, disrupted photosynthesis, and eventually cell death.³ The goal with borax application is to push boron levels high enough that Creeping Charlie reaches that toxic threshold while your grass stays just below it. In practice, that window is razor thin.

The Standard Borax Recipe

The recipe that has circulated for decades comes from early extension-service trials and goes roughly like this: dissolve about 10 ounces of 20 Mule Team Borax in 2.5 gallons of warm water, then spray evenly over 1,000 square feet of lawn. You want complete, even coverage of the Creeping Charlie foliage, but not puddles or runoff. The math matters because borax is not a conventional herbicide with a built-in safety margin. Applying too much, or applying it to a smaller area than you estimated, pushes your lawn past the damage threshold.

A few practical details on mixing and application:

• Dissolving: Borax dissolves slowly in cold water. Use warm (not boiling) water and stir thoroughly. Undissolved granules sitting on turf will create concentrated burn spots.
• Measuring your lawn: Pace off the treatment area before you mix. Applying a batch meant for 1,000 square feet over 500 square feet doubles the effective dose.
• Sprayer choice: A pump sprayer gives you the most control. A hose-end sprayer makes even coverage harder to achieve, and a watering can tends to deposit too much in some spots and too little in others.
• Timing: Apply when Creeping Charlie is actively growing and temperatures are moderate. Late spring and early fall are the usual windows. Research on boron-based ground ivy control found strong results from October applications evaluated the following summer.⁴
• Application limit: Do not apply more than once per year on the same area. Boron accumulates in soil and does not break down the way organic herbicides do.

The recipe is straightforward, but people routinely get into trouble with it. The most common mistake is eyeballing coverage area. A yard that “looks like about 1,000 square feet” can easily be 600 or 700, and that miscalculation alone can torch your grass.

The Turf Damage Problem

This is where the popular advice and the research findings diverge sharply. A controlled study testing borax, boric acid, and a commercial boron product (Solubor) for ground ivy control in Kentucky bluegrass found that while all boron products reduced ground ivy cover by 77% or more at higher rates, every one of them also caused unacceptable turfgrass injury and reduced turf quality below acceptable levels.⁴ The researchers were not testing wildly excessive amounts. They were testing rates in the range that people actually use. The conclusion was blunt: boron can control ground ivy, but not without injuring bluegrass.

The damage shows up as yellowing, thinning, and brown patches in the turf, sometimes appearing a few weeks after application, sometimes not fully visible until the following growing season. Your grass may recover if the damage is mild, but severe boron injury can kill sections outright. And because boron persists in the soil, reseeding or patching those bare spots is not as simple as it would be after a regular herbicide treatment. The boron is still there waiting for whatever you plant next.

Broadleaf weeds other than Creeping Charlie will also be killed or damaged. If you have clover, violets, or other broadleaf plants growing alongside Creeping Charlie, they will likely suffer the same fate. This is not necessarily a downside if your goal is a pure grass lawn, but if you maintain a mixed lawn or have nearby garden beds, the collateral damage is worth considering.

Soil Factors That Affect How Borax Behaves

One reason borax results vary so widely from yard to yard is that soil type and pH dramatically change how available boron is to plant roots. Sandy soils release boron to plants much more readily than clay soils. Research on boron availability showed that plants grown in coarse-textured (sandy) soil had the highest uptake of boron per unit of water-soluble boron, while plants in fine-textured (clay) soil had the least.⁵ If you have sandy soil, the borax recipe that “worked fine” for your neighbor with clay soil could be devastatingly strong in your yard.

Soil pH adds another variable. As soil becomes more alkaline (pH rising toward 7 and above), boron becomes increasingly fixed in the soil and less available to plants. A study on boron uptake by fescue found a 2.5-fold drop in boron recovery at pH 7.4 compared to lower pH levels.⁶ That might sound like alkaline soil gives you a safety buffer, but it also means the borax is less effective at killing Creeping Charlie in those conditions. Meanwhile, in acidic, sandy soil, the same amount of borax becomes highly available and potentially far more damaging to everything growing there.

None of the online borax recipes account for soil type or pH. They give you a one-size-fits-all rate that may be too weak to work or too strong for your lawn, depending on conditions you probably have not tested. This is a fundamental limitation of the DIY approach. You are applying a substance with a very narrow effective-to-damaging range without knowing how your soil will mediate its availability.

What Happens to Your Soil After Application

Unlike most conventional herbicides, which break down through microbial activity or photodegradation, boron is an element. It does not decompose. Once you add it to your soil, it stays until it is leached out by water percolating through the soil profile. In sandy soils with good drainage and regular rainfall, boron leaches relatively quickly. In clay soils or compacted urban soils, it can linger for months or even years.

This persistence matters because boron toxicity is not limited to plants. Boric acid shows broad toxicity across soil organisms, with springtails and certain worm species among the most sensitive.¹ These organisms are part of the decomposition and nutrient-cycling processes that keep your soil healthy. Repeated borax applications in the same area could degrade soil biology over time, making it harder to maintain a thick, competitive lawn, which is the very thing that would help crowd out Creeping Charlie naturally.

There is also the matter of runoff. If borax washes off your lawn and into a garden bed, you can damage ornamental plants. Dicots are broadly more sensitive than monocots, so your perennials, vegetables, and shrubs are more vulnerable than your grass.¹ Apply borax when rain is not expected for at least 48 hours, and avoid slopes where the solution could flow toward garden areas or storm drains.

Iron-Based Alternatives

The same study that documented turf damage from boron products also tested Fiesta, a chelated iron herbicide (iron HEDTA). The results were strikingly different: Fiesta at its high rate reduced ground ivy cover comparably to the boron products, but caused no observable turfgrass injury and no reduction in turf quality.⁴ Iron-based herbicides work by a different mechanism: they overwhelm broadleaf plants with iron, which causes rapid cell damage in susceptible species while grasses tolerate much higher iron levels.

Iron-based products are available to homeowners under various brand names (Fiesta, Iron X, and similar formulations). They tend to cost more than a box of borax, but they offer a much wider safety margin for your turf. They are also approved for organic lawn care in many jurisdictions, and they break down into iron compounds that are actually beneficial to soil in normal amounts. The main trade-off is that iron-based herbicides often require repeat applications, especially for heavy Creeping Charlie infestations, because they work primarily as contact killers rather than systemic ones. You may need two or three applications spaced a few weeks apart to get thorough control.

Other Approaches That Compete With Borax

If you are weighing borax against the full menu of Creeping Charlie control options, a few other strategies deserve mention:

• Triclopyr-based herbicides: Products containing triclopyr (often sold as brush killers or broadleaf weed killers) are the most reliably effective chemical option for Creeping Charlie. Triclopyr is a synthetic auxin herbicide that causes uncontrolled growth in broadleaf plants while leaving grasses unaffected. Two applications in fall, spaced about two weeks apart, typically achieve strong control.
• Hand pulling: Creeping Charlie spreads by stolons (runners) that root at every node. Pulling it by hand can work in small patches, but you need to remove every rooted node, which is tedious in large areas. Any fragment left behind will regrow.
• Smothering: Covering infested areas with cardboard or heavy black plastic for several weeks during the growing season can kill Creeping Charlie by excluding light. This also kills the grass underneath, so it is best suited for areas you plan to reseed or replant from scratch.
• Improving growing conditions for grass: Creeping Charlie thrives in shade, moist soil, and thin turf. Pruning tree branches to increase sunlight, adjusting irrigation, overseeding with shade-tolerant grass cultivars, and mowing at the correct height can all help your grass outcompete Creeping Charlie over time. This is not a quick fix, but it addresses the conditions that invited the weed in the first place.

None of these are as inexpensive as a box of borax, and some require more effort or repeated treatments. But they all offer either better selectivity (killing the weed without killing the grass) or a longer-term solution to the underlying conditions.

If You Decide to Try Borax Anyway

Some people read all the caveats and still want to try borax, either because they have a small problem area, because they prefer a pantry-item approach, or because the lawn in question is not one they are trying to maintain to a high standard. If that is you, a few guidelines can improve your odds:

Test on a small patch first. Pick a section of your lawn where Creeping Charlie and grass grow together, apply the standard recipe to that area alone, and wait four to six weeks. You will be able to see how your specific grass and soil respond before committing to the whole yard. If the grass yellows badly or thins, you have your answer without having damaged the entire lawn.

Measure the area accurately. Use a tape measure or a measuring wheel. The single most controllable variable in this whole process is getting the dose right for the area, and eyeballing it is the single most common source of problems.

Do not repeat the application in the same year. Even if the first round does not fully eliminate the Creeping Charlie, a second application will push boron levels higher and dramatically increase the risk of lasting soil contamination and turf damage. If one application does not provide satisfactory control, switch to a different method the following year rather than doubling down.

Accept that some turf damage is likely. Research consistently shows that the rates needed to meaningfully reduce ground ivy also cause at least some injury to cool-season turfgrasses.⁴ If you are willing to overseed thin areas in the spring following a fall application, the grass can recover. If a pristine lawn through the process is the goal, borax is the wrong tool.

Why Creeping Charlie Keeps Coming Back

Regardless of which control method you choose, Creeping Charlie has a frustrating tendency to return. The plant spreads both by seed and by stolons, and a single surviving fragment can recolonize an area within a season. Seeds can persist in soil for years. And because Creeping Charlie often dominates in conditions that are marginal for turfgrass (shade, damp, compacted soil), killing the existing plants without changing those conditions simply opens the space for the next round of Creeping Charlie seedlings or stolons creeping in from a neighbor’s yard.

This is why long-term control almost always requires a combination of removal (whether by borax, iron herbicide, triclopyr, or manual pulling) and cultural changes that tip the balance toward grass. Aerating compacted soil, correcting drainage issues, overseeding with competitive grass varieties, and increasing light penetration are all part of making the site less hospitable to Creeping Charlie in the future. None of them are dramatic interventions, but stacked together they create conditions where your grass can hold its ground after the weed is removed. Without those changes, you are likely to be fighting the same battle again in a year or two, regardless of whether you used borax or something else.