Spraying vinegar on grass can have several effects depending on the type of grass, how much vinegar is used, and how often it is applied. Vinegar contains acetic acid, which at full strength can kill plants and grass. However, diluted vinegar can be used as an effective weed killer and grass growth inhibitor. Here’s a quick look at what spraying vinegar does to grass:
Kills Weeds
One of the main benefits of spraying diluted vinegar on grass is that it kills weeds. The acetic acid in vinegar is an effective contact weed killer. It works by dehydrating and destroying the above ground growth of unwanted plants and weeds like dandelions, plantain, and clover growing in lawns.
Vinegar is not a selective herbicide, so it will kill any plant it comes into contact with. However, at the right dilution, it can be safely applied to established lawns without damaging the grass. The acetic acid kills only plant tissue it touches directly, so spraying carefully just on undesired weeds is effective.
Prevents Grass Growth
In addition to weed control, spraying vinegar can also inhibit grass growth. This effect can be useful when wanting to control grass height or create dead patches and edges in a lawn design. The acetic acid contacts and burns grass leaf blades and stems, turning them brown. It also destroys the waxy cuticle layer on leaves, causing dehydration damage.
Repeated applications of diluted vinegar will prevent regrowth and kill grass plants. For grass growth inhibition, higher vinegar concentrations and more frequent applications are required compared to weed control. Take care when using vinegar as a grass growth inhibitor, as it can easily kill desirable grass if over-applied.
Kills Moss
Moss is a common weed problem in lawns growing in shady, damp areas. The acetic acid in vinegar penetrates and kills moss on contact. Vinegar solutions of 10-20% acidity work well for moss control. The vinegar dries out moss, turning it black. Repeat applications are likely needed for total moss elimination.
Vinegar works best on moss when applied during dry, sunny weather. Sunlight helps activate and maximize the acetic acid effects. Vinegar is safe for grass and other plants when sprayed directly on moss growth. Avoid runoff to prevent unwanted damage in the surrounding lawn.
Lowers PH
Vinegar is naturally acidic with a low pH. Applying vinegar to lawns will lower the pH of the soil over time. This can be beneficial for alkaline soils needing a more neutral pH for optimal grass growth. However, drastic drops in pH can negatively impact beneficial microbial activity in the soil.
Apply vinegar spray judiciously for lowering soil pH, starting with light applications. Test soil pH regularly to determine if sufficient lowering has been achieved. Only re-apply if pH remains too high. Consider applying lime if pH drops excessively from vinegar spraying.
Kills Insects
The acetic acid in vinegar can be effective at killing some insect pests when sprayed directly. Soft-bodied insects like aphids, mealybugs and spider mites are susceptible as vinegar dehydrates their exoskeleton and tissues.
For insect control, stronger vinegar concentrations around 20% acidity are ideal. Spot treatment of infested areas helps prevent widespread lawn damage. Avoid excessive runoff into soil and use caution applying to blooming plants, as vinegar may injure or kill pollinating insects.
Damages Grass at High Concentrations
Although diluted vinegar can be safe for established lawns, higher concentrations or over-application of vinegar can cause grass damage. Burning, browning, stunting and death of grass plants are possible if vinegar is used incorrectly or excessively.
Always dilute vinegar significantly according to label directions when spraying in lawns and grassy areas. Test small sections first. Avoid applying at the hottest times of day or allowing spray drift onto grass. Monitor for symptoms of grass damage, discontinuing use if evident.
May Stress or Kill Other Plants
Take care when spraying vinegar around gardens and landscaped beds, as desirable plants can be damaged. Vinegar does not discriminate when it contacts vegetation, potentially causing unwanted damage. Use a shield when spraying near ornamentals.
Avoid spraying blooming plants. Vinegar can kill pollinators visiting flowers. Monitor plants for signs of injury after application and discontinue use if damage occurs. Dilute vinegar spray and carefully target applications when using around valued vegetation.
Environmental Effects
Vinegar poses relatively low risk of environmental effects when used properly for lawn and garden care. It breaks down quickly in soils, leaving no toxic residue. There are no risks of groundwater contamination with vinegar as long as label directions are followed.
Avoid excessive use and runoff into nearby waterways, as vinegar can lower water pH temporarily and negatively impact aquatic organisms. Use up diluted vinegar spray mixtures promptly rather than storing for prolonged times to prevent accidental environmental releases.
Effects on Soil
Vinegar can impact soil biology and chemistry with repeated high volume use. As an acid, vinegar lowers pH when applied to soils. It also can kill beneficial microbes like fungi and bacteria in high concentrations and with heavy use over time.
These impacts are usually temporary, as soil pH and microbes recover. But best practices are to use vinegar judiciously, target spray only on weeds, rotate weed control methods, and limit overall vinegar use. Test and monitor soil pH and biology to catch any persistent changes.
Effects Last 1-2 Weeks
The effects of vinegar on weeds and grass growth are not long-lasting. Vinegar solutions break down quickly as the acetic acid evaporates. Repeat applications are needed every 1-2 weeks for sustained weed control.
Vinegar is not a permanent weed or growth inhibitor. Persistent problems will require repeated use of vinegar or rotation with other organic methods like corn gluten applications. Plan ongoing management rather than once and done control.
Improves Lawn Appearance
Spraying vinegar selectively on weeds in lawns can greatly improve the lawn’s appearance. Weed-free, lush grass enhances curb appeal and aesthetic quality. Vinegar eliminates unwanted dandelions, clover and moss for a more uniform, manicured look.
Spot treat sporadic weeds or do blanket applications for lawn-wide weed removal. Time applications for optimal weed susceptibility. For example, target young, actively growing weeds in spring. Follow up with repeated applications for best lawn appearance over time.
Natural and Organic
Vinegar weed control sprays are derived from natural fermentation and acetobacter processes. They contain no synthetic chemicals, toxins or pesticides. This makes vinegar a safe, organic herbicide option compatible with environmentally friendly lawn care practices.
Vinegar breaks down completely in the environment over time without leaving behind chemical residues. Use vinegar to maintain organic lawns and landscapes or where chemical-sensitive individuals may be present, like children’s play areas and schools.
Cost Effectiveness
Vinegar is inexpensive compared to many liquid lawn care products. Food-grade vinegars can be used, or horticultural acetic acid products purchased in concentrated form. While not as potent or long-lasting as synthetic herbicides, vinegar still provides economical weed and growth control with repeated use.
Take advantage of vinegar’s low cost by making batches of diluted spray mix as needed. Combine with other homemade remedies like salt and lemon juice for added efficacy. Just be aware that vinegar alone may require more frequent applications than commercial herbicides.
Readily Available
White distilled vinegar is readily found at any grocery store or supermarket, making it an easily accessible weed control option. No special licensing or equipment is needed to purchase and apply vinegar in lawn care. Be sure to choose new, less degraded vinegars for maximum acetic acid potency.
Keep vinegar stocked for mixing weed killing solutions anytime unwanted plants appear. Having vinegar on hand also precludes needing to make extra trips to purchase specialty herbicide products during crucial treatment windows.
Safe for Pets
Using vinegar for lawn weed control is non-toxic and safe around family pets when label directions are followed. Be sure to keep pets off treated areas until spray solutions have fully dried. Avoid over-spraying onto desired lawn grasses.
Vinegar gives pet owners, especially those with dogs who frequently play or lie in the grass, peace of mind that treatments will not harm their animals. Vinegar also breaks down completely, leaving no lingering chemical residues to pose oral or dermal risks to pets.
Potential Drawbacks
While vinegar has many benefits, there are some potential drawbacks to consider when using it as an herbicide:
- Acidity can damage lawn grass and other plants if over-applied
- May kill beneficial insects like bees and ladybugs
- Can leach nutrients from soil with repeated high volume use
- Lower efficacy than synthetic chemical herbicides
- Effects only last 1-2 weeks
- Cannot selectively kill grassy weeds in lawns, only broadleaf weeds
- May need to spray late in day to avoid rapid drying
- Rainfast only for a few hours after treatment
How to Apply Vinegar for Best Results
Follow these tips for maximum efficacy when using vinegar as an herbicide:
- Use horticultural vinegar with at least 10% acetic acid for best results
- Dilute vinegar with water according to label rates, usually 1:1 to 1:3 vinegar to water ratios
- Add a small amount of dish soap to help the vinegar solution stick to leaf surfaces
- Spray weeds thoroughly on a sunny day with temperatures above 60°F
- Target young, actively growing weeds for best control
- Re-apply every 7-14 days for sustained effects
- Use a pump sprayer for targeted spot treatment of individual weeds
- Adjust nozzle to coarse spray pattern to avoid drift onto desirable plants
Alternative Natural Herbicides
Other natural weed killing options to possibly use along with or instead of vinegar include:
- Corn gluten meal – prevents seed germination
- Citrus oil – damages cell membranes
- Salt water – creates osmotic pressure
- Boiling water – thermal damage to plants
- Soap-based herbicides – disrupt cell membranes
- Essential oils like clove, thyme, citrus – act as plant growth regulators
Rotate using vinegar with other natural herbicides to prevent weeds from developing resistance. You can also tank mix vinegar with items like lemon juice, soap or oils for added effectiveness compared to vinegar alone.
When to Avoid Vinegar
Hold off on using vinegar weed spray in these situations:
- Temperatures exceeding 85°F – increased risk of lawn damage
- During drought or heat waves – plants already stressed
- Prior to seeding new lawns – can inhibit grass germination
- On newly emerged grass seedlings – damage young tender growth
- Near bodies of water – potential risks to fish and aquatic life
- Widespread application in landscapes – may kill valued vegetation
- On blooming plants – can kill visiting pollinators
Spot Test First
It’s always advisable to test vinegar herbicides in a small, inconspicuous area before widescale spraying. This gives experience with solution mixing and calibration while assessing results and potential plant damage:
- Mix vinegar solution at intended concentration and amount
- Spray a 1-2 square foot area of lawn or garden weeds
- Evaluate weed control efficacy in 2-3 days
- Inspect desirable plants for damage before and after treatment
- Adjust solution strength and application volume if needed
- Proceed to large scale spraying once comfortable with small area results
Vinegar Weed Control vs Other Chemical Herbicides
Vinegar weed killers have both pros and cons compared to synthetic chemical herbicides like 2,4-D, dicamba, glyphosate, and others:
| Vinegar | Chemical Herbicides | |
|---|---|---|
| Effectiveness | Moderate weed control with repeated applications every 1-2 weeks | Very effective control, often one application eradicates weeds for a season |
| Selectivity | Non-selective, can damage any plants it contacts | Some types selective and will not harm certain plants like lawns |
| Cost | Very inexpensive, diluted vinegar treatments cost pennies | Can be expensive for commercial weed killers |
| Environmental Impact | Minimal impact, acetic acid breaks down rapidly | Some herbicides linked to environmental and human health risks |
| Toxicity | Non-toxic but can damage plants from high acidity | Many synthetic herbicides require careful handling to avoid risks |
Conclusion
Spraying diluted vinegar can provide effective, natural weed control in lawns and gardens. It controls a variety of weed types, while also inhibiting grass growth when desired. Vinegar offers a safe, non-toxic alternative to synthetic herbicides. However, it needs repeat applications for sustained effects. Follow directions carefully and do not over apply to avoid unwanted plant damage. Test vinegar first in small areas to fine tune solution strength and application technique before widescale spraying.
