V_coerulea wrote:
Manure like Steve suggests is probably one of the best ways so long as it is
thoroughly decomposed. In any case, you wouldn't use lime to make the soil
more acid. Lime would make it even more basic than you are already. For
quick drops in pH, aluminum sulfate is usually recommended. Powdered sulfur
should drop it over the long run along with the added compost. Manure itself
would help buffer the pH and not really acidify the soil but maybe help
neutralize it on top of the other benefits supplied by the organic material
including moisture retention.
I hope the kids get a good crop.
Gary

I agree with all the comments and advice you give, except the use of
aluminium sulfate to lower pH. Aluminium salts have been linked with
health problems, in particular, increasing the development of Alzheimers
disease. My suggestion for lowering pH (beyond the excellent ones of
compost and powdered sulfur) is to add citric acid, which you might be
able to get in pharmacies or even ethnic food shops, or pine needles are
very acidic if I recall correctly. In terms of ease of finding and cost,
sulfur might be the best, but it is apparently easy to add too much and
end with very acidic soil.