Why does my vinegar solution not work?
Written by
Nguyen Minh
Reviewed by
Prof. Martin Thorne, Ph.D.Vinegar solutions fail if the concentration of the vinegar or the timing for use is not properly thought through. I've tried using weak vinegar (less than 5% acetic acid), but it didn't effectively burn the weed foliage. If you use it on a cool day, it tends to dehydrate the weeds much more slowly. I learned this with my very first batch, where I sprayed a batch of mature dandelions. You've got to have the right conditions and the right scale of ingredients.
Ingredient Issues
- Low acidity vinegar under 5% lacks sufficient burning power
- Missing salt reduces dehydration capacity for root damage
- No dish soap prevents adhesion to waxy weed surfaces
Application Errors
- Cool temperatures below 60°F slow plant metabolism
- High humidity reduces evaporation and effectiveness
- Overspray dilution from nearby sprinklers or rain
Strike young weeds less than 4 inches tall. Mature plants are coated with wax and will fight your vinegar. Treat them within their first two weeks of life. I mark new weeds in a journal each week. You catch invaders before they shoot poison darts.
Increase salt content for tough perennial weeds. Add 1/2 cup of salt per liter of vinegar and dissolve thoroughly before adding soap. Use rock salt instead of table salt for better dehydration. I mix the salt into the warm vinegar to help it dissolve more easily. In so doing, you greatly increase your power to kill roots.
Apply under heat 10 AM to 2 PM when plants are actively taking up water. A sunny day will stress the plant, causing it to desiccate faster, as the leaf pores open. Don't hit them on a windy day, either, or it will drift over other things. I use a pump sprayer. You will achieve better uptake when the application is made at the optimum time for plant activity.
Test new mixtures on small patches of weeds first. Observe the result in 48 hours before proceeding with the full application. Adjust the salt or soap ratios to achieve the desired results. I keep a test area adjacent to the compost bin. You do likewise for weeds that persist in your landscape.
Read the full article: 10 Natural Weed Killers That Work
