On 6/7/10 2:52 PM, Paul M. Cook wrote:
I have a box of Fix-All wall patching compound. It is gypsum, lime, starch
and some other inert ingredients. What would be a good formula for
tomatoes? My tomatoes are growing very fast and setting fruit. I know they
need calcium. Would this be good for other plants like peppers and cukes?



You should not apply lime unless you know your soil is acidic.

The soils in my area are quite alkaline. I broadcast sulfur and various
sulfates every year and use acidic fertilizers. If I didn't, many of my
plants would have chlorosis. My compost is actually leaf mold, which is
more acidic than the usual compost.

Gypsum by itself is a good source of calcium, and it's quite
inexpensive. Buy it and forget about using plaster.

Alternatively, dig bone meal into the soil before planting tomatoes.
Dig it deeper than the existing tomato roots. Bone meal not only
provides calcium; it also provides phosphorus, which promotes flowering
and the subsequent formation of fruit. But to be effective, it must be
placed where roots will find it since phosphorus does not readily
dissolve and leach through the soil.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening diary at http://www.rossde.com/garden/diary