Does Vinegar Kill Weeds in Concrete?

Does Vinegar Kill Weeds in Concrete? Natural Weed Killer Recipe

Yes, vinegar can effectively kill weeds in concrete cracks when mixed with salt and dish soap. This natural solution is safer than chemical herbicides and works well for small-scale weed control. This guide covers the exact recipe and how to use it effectively.

Why Vinegar Works

Vinegar (acetic acid) kills weeds by:

• Acidic burn: The acid burns plant tissue
• Desiccation: Draws moisture out of plants
• Cell damage: Destroys plant cells on contact

However, household vinegar (5% acidity) is often too weak. Higher concentration works better.

The Effective Recipe

For best results, use this combination:

Ingredients

• 30% Vinegar: Horticultural vinegar (stronger than household 5%)
• Salt: Table salt (sodium chloride)
• Dish Soap: Liquid dish soap (acts as surfactant)

Recipe

• 1 gallon 30% vinegar
• 1 cup table salt
• 1 tablespoon dish soap

Why Each Ingredient

30% Vinegar: Strong enough to kill weeds effectively (household 5% is often too weak)

Salt: Prevents regrowth by making soil inhospitable

Dish Soap: Helps solution stick to leaves and penetrate better

How to Apply

Proper application ensures effectiveness:

Step 1: Prepare the Solution

1. Mix ingredients thoroughly
2. Salt may need to dissolve—stir well
3. Pour into spray bottle or garden sprayer

Step 2: Apply to Weeds

1. Spray directly on weeds in cracks
2. Cover all leaves and stems
3. Avoid surrounding grass (will kill it too)
4. Apply on sunny day for best results

Step 3: Let It Work

• Weeds should show damage within hours
• Complete kill takes 24-48 hours
• Don't rinse—let it work

Step 4: Remove Dead Weeds

• After 24-48 hours, remove dead plant material
• Pull or scrape out of cracks
• Clean crack thoroughly

Step 5: Seal the Crack

To prevent regrowth permanently:

1. Clean crack completely
2. Fill with flexible polyurethane sealant
3. This prevents new weeds from taking root

Safety Considerations

30% vinegar is strong and requires care:

• Wear gloves: Protects skin from acid
• Wear eye protection: Prevents splashes
• Protect surrounding plants: Will kill any plant it touches
• Keep away from pets: Until dry

Limitations

Vinegar solution has some limitations:

• Contact killer only: Kills what it touches, not roots deep in cracks
• May need multiple applications: Stubborn weeds may require repeat treatment
• Not selective: Kills all plants it touches
• Doesn't prevent regrowth: New weeds can still grow unless crack is sealed

For Permanent Solution

Vinegar kills existing weeds, but sealing the crack prevents new ones:

1. Kill weeds with vinegar solution
2. Remove dead plant material
3. Clean crack thoroughly
4. Seal with flexible polyurethane sealant

Sealed cracks prevent weeds from taking root permanently.

The Bottom Line

Yes, vinegar kills weeds in concrete when mixed with salt and dish soap. Use 30% vinegar (stronger than household), mix with salt and dish soap, apply directly to weeds, and let work 24-48 hours. However, this only kills existing weeds—seal the crack after treatment to prevent new weeds from growing. For permanent weed elimination, always seal cracks after killing weeds.

Need help with weed removal and crack sealing? Contact Local Concrete Contractor. We can help eliminate weeds and seal cracks permanently.