Raised garden bed help please...

[Dace]

I posted this over on the SS board but figured I could probably get some good feedback here

I want to put in 2 5X20 raised beds. Here are my options...
Rent a tiller ($100 for the day) and till the areas and then build 12' raised beds
~ OR~
Build deeper beds like 24" and just do a lasagna layer at the bottom.

Pro and cons.....well renting the tiller will get the job done properly but I will still have to scrounge/spend money on compost to fill the bed, but it would be mixed with the natural soil.

With deeper beds I will really have to work hard to get enough fill and it would be pretty much compost, and be lacking in the natural soil microbes, but I will be able to spend more on soil amendments etc.

My soil is very rocky and compact.

Any feedback would be helpful!

Also, I just found an ad on CL for organic compost $20 for 1 Cubic yard and buy 5 get the 6th CY free...and they will deliver. How much would my 2 100sq foot beds need if they were 24' deep??
http://sandiego.craigslist.org/nsd/grd/1237676398.html

 

[vfem]

ok...24" is rediculous! 12" is more then enough even. Mine are all 12" and I filled one 5x5' bed with just over 1/2 a SY. I hope that helps.

When are you planning on planting in this bed?! I think right away is a bad idea... however... if you want to prep this for a late summer or fall garden.... go ahead and scrap up the ground underneath with a hoe OR use a weed whacker super close to the ground. Then lay a layer of cardboard or Newspaper over where you are building the raised beds. Soak the paper or cardboard with a hose and then fill the top with the soil. Let it sit awhile. Spray it with the hose to help decompose the newspaper on and off for a few weeks. Then let nature do its thing. You should be able to plant it and not have to worry about weeds this fall.

I did this with mine in the late fall and some in January... everything was done and ready for me to plant in march.

 

[Dace]

My worry is not the weeds, the soil is impossible to dig...hence the idea of a 24" deep raised bed...the plants would be able to penetrate down much deeper and over time the ground underneath would soften and allow even better growth.

 

[vfem]

Honestly, I have CLAY for soil.... 12" is more then enough.... even for carrots!

 

[patandchickens]

I answered over on the SS site, but to summarize, no way do you need 24" (except for handicap issues or to grow something like trees on a concrete slab). The vast majority of plant roots are in the top 8" or so of the soil, and while many do benefit from being able to get their toes down deeper they do not require it nor do they require the lower levels to be particularly good soil.

The native soil under your raised bed will slowly uncompact and improve itself as time goes by, just by virtue of being sat on by a layer of good well-tended soil. If it is hardpan, break it up first by tilling or digging or pickaxing, then till in some compost, make a normal raised bed (12" or less) and you're totally good to go.

Have fun,

Pat

 

[detali]

I did a lasagna type of a garden when I lived in Tucson.

I dug a pit 3'x15', 18 inches deep, for each bed and layered into it everything organic I could get my hands on, cardboard, straw, palm branches, some native soil, garbage produce from a vegetable market, soil amendments,etc, more native soil. I finished off the top by adding some bought potting soil. That garden went wild with productivity.

Now in San Manuel I'm having to start all over again.