Do home remedies actually kill weeds?

By The Weed Guy·Last updated 2 September 2026

Not the ones that get shared around, and they all fail for the same reason. Boiling water, vinegar and salt are contact treatments: they burn or dry out the part of the weed they physically touch, and nothing else. On a drive or patio the root is down in the jointing sand and the sub-base, out of reach of anything poured on top, so you get a fortnight of clear-looking paving and then the same weeds again. Line them up and only one question sorts them out: does it reach the root. Here is how each answers it, and what happens when you keep repeating them.

Boiling water is the one I would least worry about, and the only one on the list I would actively tell you to use in the right spot. It is free, it leaves nothing behind in the ground, and on a seedling in a crack or a young weed you have just spotted, a kettle poured slowly straight onto the crown will finish it. Its limit is physics. The water cools the moment it soaks in, so it only kills the tissue it actually reaches, and horticultural advice on this is consistent: boiling water will not kill roots or other plant parts down in the soil, and anything with an established root system resprouts within a few days. The rule I would give you is about the weed, not the liquid. If you could still lever it out whole with a screwdriver, a kettle will finish it. If you could not, no kettle is going to either.

Vinegar gets talked up the most and works in exactly the same way. Acetic acid is a contact herbicide that burns the foliage it lands on and does not travel into the root. Kitchen vinegar is around 5 percent acetic acid, which will brown off young, tender top growth and not much more, so an established drive weed wilts and then regrows a week or so later from a root nothing ever touched. Herbicidal strengths are quoted at 10 to 20 percent, and that is where it stops being a kitchen ingredient. Extension advice is that vinegars of 11 percent acetic acid and above can burn skin and cause severe eye injury, including blindness, and the amenity vinegar product Oxford City Council assessed in its 2023 review of glyphosate alternatives carries the COSHH corrosive warning symbol. If you are reaching for the horticultural stuff, you are handling a corrosive chemical and it wants treating as one.

Salt is the one that leaves a mess behind, and the mess is mostly in the ground rather than on the slab. It dries the top out and kills it, but salt also accumulates and sterilises the soil it washes into, and flushing it back out takes a lot of rain over a long time. On a drive, the soil it washes into is the bedding layer and the sub-base under your blocks, and it does not stop at the edge of the paving either, which is why the standing advice is to keep it well away from borders and lawn edges. It is the one remedy here where the cure can outlast the weed by years, and it still never touches the root.

Bleach I have given a page of its own, because its problems are not the same problems. The short version: it is an oxidiser rather than a herbicide, so it burns the leaf and never reaches the root like the rest of them, but it brings risks the others do not, including a hazard statement on the label warning that contact with acids liberates toxic gas. That is what makes the popular bleach and vinegar mix a genuinely bad idea rather than merely an ineffective one. If bleach was what you were about to try, the full answer on it is on its own page below.

If you want to know how the repeat cycle actually plays out, the best evidence in this country is not on gardening websites. It is in the councils that have tried to come off glyphosate on exactly this kind of hard surface. Bristol trialled acetic acid and hand weeding in 2017 and found the weeds started to re-emerge within a month, while comparison sites treated with glyphosate stayed low for five to six months. Redbridge trialled a vinegar-based spray the same year and abandoned it at the start of the second treatment because it had not fully killed the weeds. Oxford's 2023 review budgets three glyphosate applications a year against four for acetic acid, and every two weeks from March to October if you are doing it mechanically instead. That is measured, public, and about as close to your own drive as this evidence gets.

So the pattern is the same whichever one you pick, and that is the real finding here. Boiling water, vinegar, salt and bleach all answer no to the only question that matters, because all four affect the tissue they physically touch and nothing beyond it. It looks brilliant on day two, acceptable on day ten, and by week three the same weeds are back through the same joints. A systemic weedkiller answers yes: the plant draws it in through the leaf and carries it down into the root itself, which is why it takes two to four weeks rather than two days, and why you do it once instead of every fortnight all summer. Worth knowing too that HSE's line on the kitchen-cupboard route is that using common household chemicals as a plant protection product is not without risk, and is not always legal.

One last thing if this is a drive or a patio rather than a border. Every repeat visit costs you jointing sand. The paving manufacturer Marshalls says weed removal often takes some of the sand with it and that it needs replacing as soon as the surface is clean, because partially filled or empty joints are detrimental to pavement performance, and an empty joint is exactly where the next seed lands. The fortnightly kettle-and-vinegar routine is not neutral, then. It opens the joints up and reseeds the problem it is meant to be solving. So: boiling water on a seedling, by all means. For anything established, a systemic weedkiller at the label rate on a dry day, and then the joints refilled with kiln dried sand.