Nick Maclaren wrote:

| When vinegar is used as a herbicide, does it act systemically?

That is not a question :-)

? You mean all herbicides ARE systemic? What I meant, more accurately
I admit, is "When vinegar is used instead of a herbicide but for the
same purpose as a herbicide, does it act systemically?"

| I would like to use vinegar on the grass, provided it has a permanent
| effect on the roots.

Not merely doesn't it have a permanent effect on the roots, it
doesn't have a significant effect on the leaves. It is purely and
simply a weak acid. You shouldn't take so much notice of the New
Age Merkins (which is where I assume that you heard of vinegar as a
herbicide and the other myths you have picked up).

No, actually the United States Department of Agriculture is doing a lot
of investigation into the use of vinegar and apparently USA garden
centres have long stocked strong vinegar specifically for this purpose.
All news to me too, but true. See:

http://search.usda.gov/search?q=vine...esheet=ARS&oe=

Glyphosate should do what you want, and will not impair the planting
of groundcover, but may need several applications for deep-rooted
perennial weeds. It will not cause the trouble you are afraid of
in any normal soils. Alternatively, sodium chlorate will degrade to
salt, which will wash away, but will need repeated applications.

Thanks very much, Nick, for your assurance re. Glyphosate. Have you
used it yourself for turning a lawn into a garden?

My concern about it was triggered by the following summary of research:

http://unofficiallyoptimistic.com/?p=24

Eddy.