Express.co.uk tested four homemade weed killers on patio weeds: rock salt with boiling water, white vinegar with washing-up liquid, lemon juice, and plain boiling water. Two methods delivered instant results, while the others proved ineffective.
Rock Salt and Boiling Water: Instant Results
Angela Patrone tested rock salt on broadleaf and crabgrass weeds invading her patio. She sprinkled rock salt directly onto the weeds, then poured boiling water over them. Within an hour, the leaves and stems began to wilt and turn brown. Nine hours later, the weeds were completely dead and easily removed with a screwdriver. After two weeks, no weeds had reappeared.
White Vinegar and Washing-Up Liquid: Effective Within Hours
Phoebe Cornish tested white vinegar on weeds sprouting through cracks in her driveway. She mixed just under 500ml of distilled white vinegar with a quarter teaspoon of washing-up liquid, following Martha Stewart's method. After spraying the solution onto the weeds, they appeared bleached and withered within hours. The next day, the weeds came out at the root far more easily than untreated ones.
Craig Elworthy, founder of Lawnbright, advises: "Allow the vinegar weed killer to sit on the weeds for several hours or overnight. You should notice a big difference by the next day."
Lemon Juice: Ineffective
Ketsuda Phoutinane tested lemon juice on weeds between paving slabs. She used juice from three lemons (about 100ml) and coated the weeds' foliage and roots. After 24 hours, the weeds appeared more vigorous. Heavy rainfall may have washed the juice away, but the test was deemed unsuccessful.
Boiling Water Alone: Limited Success
Sophie Law tested plain boiling water on a dandelion in gravel. The leaves and flower drooped immediately, but 24 hours later the dandelion was still alive. Boiling water alone struggles to kill deep-rooted weeds; it is most effective on small, freshly emerged weeds.
