"BenGman" wrote in message
oups.com...
how high should my raised beds be?

6in will help, 12in would be better. More than that will be more costly and
not much help except for the most deep-rooted plants, although it would be
nice not to have to bend/kneel to work your garden if you can afford it :-)
If your bed is only small you can be extravagant!

I have really crappy soil and i've
decided that i will be growing my tomatoes, carrots, and snap peas in a
raised bed. Now, i don't know deep the roots will grow, but i need to
know how deep to make the bed.
If I can't make the bed high enough, what kinds of supplements should i
put in my soil? I live in the Bay Area, California and my soil is
sorta rocky and has lots of clay. What should i put in it to be
nutritious for my plants?


If your soil is crappy just building the beds will not do very much for
nutrition but it will improve drainage (which is good) generally you need to
improve the soil anyway.

Things to add

(1) Plenty of organic matter, this will be what you can get access to and
afford to buy. For example; prepared compost, spent mushroom compost, leaf
mould, fine rotted mulch (not wood chips), rotted grass clippings, manures.
If buying fresh manure make sure it has a couple of months to rot before you
plant. Organic matter will improve texture and nutrients. In the long term
it is very handy to make your own compost continuously instead of buying it.
(2) Gypsum will help break up the clay, this is good as it improves
workability and drainage and allows plant roots to penetrate.
(3) Garden lime if the soil is too acid. Get a pH test kit, the dye
indicator sort are cheap and accurate enough for the purpose. Clay soils
are often quite acid and so is compost unless it is already limed by the
maker.

You cannot build good soil overnight, start soon and be ready for next
spring.

David