Vinegar in the Garden: What Works, What Doesn't, and Surprising Uses

Vinegar (5% acetic acid) is touted as a miracle garden product — but science says it's a poor fertilizer, temporary pH adjuster, and non-selective herbicide that kills tops but not roots. Here's the reality check, plus where vinegar actually shines.

Myths Debunked

• Fertilizer? No — only carbon, hydrogen, oxygen. Plants get these from air/water.
• Soil acidifier? Effects are short-lived; requires massive amounts.
• Weed killer? Burns foliage on contact, but roots survive → regrowth. Kills any plant it touches. 20% acetic acid works better but is caustic (skin/eye hazard) and still doesn't kill perennial roots.

USDA studies: 5% vinegar = unreliable weed control. Hand-pulling beats it for longevity.

Real, Proven Uses

• Cut flower preservative: 2 tbsp vinegar + 1 tsp sugar per quart water.
• Ant deterrent: Spray trails, entry points.
• Calcium remover: 1:1 vinegar/water on brick, limestone, pots.
• Rust remover: Soak tools overnight in straight vinegar.
• Skunk odor on dogs: Rub full-strength vinegar, then rinse.
• Cat repellent: Sprinkle in sandboxes, beds — they hate the smell.

Vinegar is a handy household tool — just not a garden cure-all.