Brian,

I have not tried vinegar so can't comment but when I was much younger an old neighbour who had a bountiful yard taught me this trick.

Boiling water and bleach.... kills weeds as well as ant hills. In fact it works so good on the ant hills it is all I use.

Mind you for vegetation it would be difficult to "spot weed" and not harm something right next to the weed. I use it mostly for the driveway & curbing etc.

cathy

Vinegar in boiling water got rid of ant hills in the grass and in the cracks in our asphalt driveway, but as for killing weeds, dunno. Isn't bleach harmful to the soil?

A co-worker of mine uses vinegar to kill weeds. I don't think it needs to be diluted with boiling water to be effective.

I saw vinegar recommended as a weed killer on a U.S. gardening show some time ago. He was using it to kill vines and he sprayed it on cut stems. I used it on my patio for weeds in the cracks, but I didn't find it too effective. Maybe it has someting to do with entering the cut stem of the plant.

I find vinegar kills leaves but not the root system. If a plant is young and doesn't have a root system built up it works well. An older, more established plant may come right back up.

Horticultural vinegar is about 4 times as strong as the white vinegar you buy at a grocery. It is being sold as a "green herbicide" by Scott's and others. I am trying it for the first time now. I doubt the household vinegar will be strong enough.

I tried the white vinegar full strenth on some poppies growing between my paving stones. It did shrivel them up, but after a week they were back. So.... white vinegar did not work for me.

An older farmer gave us a recipe (if I can find it!) for homemade weed killer. I know it had vinegar and salt in it, I can't remember what else. But the salt helps to strengthen the vinegar.

Won't the salt and the vinegar also change the PH balance of the soil?

Roundup doesn't. Talk to someone who is knowledgeable and has taken courses on the uses and applications of various herbicides and insecticides. I did.

Brenda (who just finished spraying about 3 gallons of roundup around the acreage and has lots more to do on this nice calm day.)

Vinegar is somewhat ephemeral in it's impact... and regular household vinegar is a bit weak. The active agent is acetic acid...some vinegars are higher in % of acetic than others. (Strong acetic acid is used to dissolve limestone.)

Salt is almost always a negative in the garden...whether in fertilier, water, herbicides, etc. Even careful use of salt products along driveways, paving stones, etc. is not recommended as it will eventually wash into surrounding areas.

http://communities.canada.com/calgaryherald/blogs/gardenbuzz/default.aspx

Vinegar is effective as a plantkiller if you are persistent in using it. One application will likely not be effective in killing a deep-rooted persistent weed. As with most 'non-commercial' type plantkillers, you must apply and re-apply regularly for it to be effective. Load up a spray bottle and spray daily!
Salt is not good for any plants and will remain in the soil for subsequent plantings.
Bleach is mostly nitrogen and does not harm the soil. Diluted 1 part bleach to 10 parts water, it makes an excellent slug killer without harming grass or most plants.

I've never used vinegar...but quake grass invaded my aspargus garden. What a mess, poor aspargus didn't have a chance. Someone told me to use salt and it would kill the quake but not bother the aspargus, Ha ! Good advice that didn't work ! I used ten pounds of salt and the quake kept right on growing and the aspargus fought the battle for two years and then gave up ! I would think that vinegar would change your soil Ph. Good Luck !

Vinegar works just fine to kill weeds - you have to get it to the roots though, leaf application does nothing. I buy it by the 2 gallon jug and use an old dish soap bottle with the top that you pop up to aim it between bricks in a path as organic alternative to roundup.

aprilwine - Maybe you are thinking of Ammonia - which is nearly all Nitrogen. Bleach has no nitrogen in it.
The chemical forumula is NaClO - Sodium Hypochlorite. That N is Na for sodium. NaCLO is a strong oxidizer and a poison. See Wikipedia for an overview. As a sterilant, it will kill all living things in the soil its applied to, including all bacteria, earthworms, etc. But its really good for cleaning tools or if you have any fungal infections in the garden.. I wipe my clippers with dilute bleach between every cut on broadleaf evergreens. I don't know what the effect is if diluted 1:10 - but if the Chlorine moves off as a gas maybe it disintegrates quickly - don't know. Having poured bleach on red ant hills, I can tell you nothing grows there for years - it completely sterilizes the spot.