raised beds

how high should my raised beds be? 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?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

We did raised beds in California up in the mountains where the soil was mostly decomposed granite. ;-)
We found around 12" or so to be enough.....
Good luck!
--
Om.

"My mother never saw the irony in calling me a son-of-a-bitch." -Jack Nicholson
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
BenGman wrote:

Tomatoes and peas don't have incredibly deep roots - obviously, carrots are another story. My beds are only about 9", but that's more for drainage than anything else.

Hey, it's the same as anywhere: Lots of organic matter. Loosens clay, feeds sand. Get a garden supply place to dump a cubic yard or so of mushroom compost on your driveway, and turn it in, along with some steer manure. It'll make a huge difference. Compost everything you can and turn it in every spring, along with more steer manure, and after a few years you'll have nice light soil that doesn't clump and is full of nutrients.
--
<http://www.midnightbeach.com

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I make a mix of top soil, sand, and compost to fill in my raised beds. I make mine only high enough to get them off the ground 8 to 10 inches, and still be able to get my tiller up into it. I raise onions, asparagus, carrots, squash Japanese radishes, and sweet potatoes.
I have a friend who always puts any grass he mows in his garden area. He lays it between the rows of veggies to keep weeds down and moisture in. Then during the fall after the garden is done, he plows/roto-tills it all together. He can grow the biggest butternut squash I have ever seen.
Dwayne

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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

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
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
g'day bengman,
yes around 10"s is sufficient.
snipped With peace and brightest of blessings,
len
-- "Be Content With What You Have And May You Find Serenity and Tranquillity In A World That You May Not Understand."
http://www.users.bigpond.com/gardenlen1
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.