Organic weedkillers in the UK use pelargonic acid, acetic acid, or heat to kill weed foliage on contact, but none destroy roots of perennial weeds. Commercial organic products from Neudorff and Vitax cost £0.50-£1.20 per square metre and kill annual weeds within 1-3 hours. Vinegar solutions need 20% acetic acid concentration to match commercial performance.
Key takeaways
- Pelargonic acid kills weed foliage in 1-3 hours but does not reach roots of perennial weeds
- Household vinegar (5% acetic acid) is too weak for effective weed control — commercial formulations use 20%
- Boiling water kills annual weeds on paths within 24 hours at zero cost
- Flame weeding destroys top growth in seconds but requires repeat passes every 7-10 days for perennials
- Organic weedkillers cost £0.50-£1.20 per square metre versus £0.08-£0.15 for glyphosate
- Deep mulching at 10-15cm suppresses 90% of annual weed germination without any chemicals
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Our team produces practical UK gardening guidance from source research, contributor records and established horticultural practice. Editorial standards are overseen by Matt W.
