moot1337

Vinegar is a very effective weedkiller because it changes the pH of the soil, and most weeds can't grow in overly acidic soil (most plants cant either, for that matter). It's a great solution for driveways and cracks in sidewalks, applied sparingly near concrete as it will dissolve that as well. Just pour some on the soil near the weed's roots and watch it die in the sun after a couple of days.

The change is completely reversible, too - unlike salt, where you've got to flush the ground with water 'till all the salt is gone, with vinegar you just mix some dolomite lime into the soil until the pH is corrected. Bleach, being a strong base, would counteract the effects of vinegar, by the way - use one or the other (I prefer vinegar, as it's more eco-friendly).

Also, the trick with Roundup and other weedkillers applied to the leaves of weeds: you have to make sure the weeds are actively growing when it is applied, and it can't be washed off the leaves for a few hours. Make sure to water them well during the summer, and apply on the morning of a nice sunny day. This way, the growth inhibitor in the weedkiller is transported all the way to the root of the weed, for a fast, complete kill. For the same reasons, it does not work well in the winter or during other periods of low growth (drought, no sun, etc.).

-m00t!

(edit to add: it is unwise to mix vinegar and bleach - chlorine gas can result, by the reaction 2HOCl + 2HAc ↔ Cl2↑ + 2H2O + 2Ac- (Ac : CH3COO))

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And that, my liege, is how we know the Earth to be
banana-shaped.
This new learning amazes me, Sir Bedevere. Explain again
how sheeps' bladders may be employed to prevent earthquakes.
Oh, certainly, sir.