Here's a real fast and quite possibly not entirely accurate description of "soil."

Half (50%) of most soil is air or water, in a constantly changing proportion between 'dry' and 'saturated'. Both air and water are usually in plentiful supply in most gardens.

Of the other half (50%) of soil, most of it (roughly 40-48% in most gardens) is made up of minerals formed from rock. In the form of sand (big particles) silt (smaller particles) and clay (smallest particles.) And just like air and water, rock-based minerals are usually in plentiful supply, in most gardens.

If you want to make the soil you have better for growing food, add lots of varied organic materials. You can do this by sheet (lasagna) composting inside your raised bed; or you can compost in a separate bin and then add the finished compost to the bed; or you can grow green manures inside the raised bed, which can help break up the soil (and subsoil) for future food gardening. Or, you can try variations on all three.

From the limited description you gave, this is what I would do.

1) Add as much leaf mold as you can (up to 6" deep) to the surface of the raised bed, as soon as you can. Then toss as much used coffee grounds on top of it as you can (up to 2" deep.) Then shallow-till those materials (4-6" deep) into the existing topsoil.

2) Two weeks later, plant a fast-growing leafy green manure crop (like clover, peas, or other legumes) which will break down quickly to increase nitrogen. Grow it for three months then cut it down (leaving the debris right where it falls on the garden bed) and then dig it under -- or smother it with cardboard or newspaper.

3) While the green manure crop is growing, make a couple cubic yards of compost with whatever other compostables you have on hand.

3) Then two weeks after digging the green manure crop under, plant another crop for extensive root and stalk growth. Something which will winterkill could be best; rye or even wheat could work. Buckwheat also produces a lot of organic materials in a short time.

4) Before the 2nd green manure crop goes to seed, chop it down and leave the materials on the ground. Water it, cover it with thick layers of newpaper and/or cardboard, top off with the compost you've made -- then plant your veggies in the fall or the following spring.

Something to remember about organic materials: they decompose. In the process, they reduce dramatically in size and bulk. About 9/10ths of whatever organic materials you add to a compost pile, or drop right on your garden, will turn into gas within a year or less. That's nine parts out of ten.

So: if you want to raise up the surface of your soil roughly two and a half inches, figure on piling up the organic materials roughly two feet high. It seems like a lot of work when you think of it in that way. However, the results of 2" of good compost applied to most soils can be spectacular. Combined with two green manure crops, you could see a very large increase in the percentage of organic materials in your soil.

There's many FAQs about soil and composting here on the forum, which can help give you lots more information about all of this stuff. See the link, below.

Good luck and have fun. :)

All the best,
-Patrick

Here is a link that might be useful: Soil, Compost and Mulch forum FAQs

Patrick is pretty close. Soil is composed of about 45 percent minerals (the material eroded from the rocks you find around you), about 5 percent organic matter (waste vegetation), about 25 percent water, and about 25 percent air. If you work enough organic matter into what every the mineral portion of your soil is you will have a good soil.
Compost is vegetative waste that has been partially digested by various bacteria and is a way to speed up the process Ma Nature uses to get the vegetative waste back into the soil so it can be used by plants for nutrients. Compost is one form of vegetative waste that all soils need to be good and healthy.
How long it takes a soil to rebuild into a good, healthy soil depends on the condition it started in and the amount of vegetative waste that is added as well as how digested that waste is when added, but figure on about 3 years after you start for the Soil Food Web to really get established. You may have some good looking soil in 4 months but it will take much longer for that soil to get into good tilth.

Redthistle asked:

"Could I expect to make soil out of this stuff in four months? What would you use to make soil?"

The answers you have already gotten are excellent in what you are trying to achieve. I can only add what I would do were this my project. Please keep in mind there are so many ways to create a productive raised bed (square foot, biodynamic, conventional, organic), thus one is only limited by personal preference/philosophy. Since you already have soil, all you are really doing is amending the soil you have with the organic matter you now have on hand or can get your hands on.

The link below leads to a post that may be just what you are looking for. The only thing I can add is that I would compost any fresh manure before adding it to the bed. I trust this helps in some small way

Blutranes

Great advice above!

I need encouragement. Another friend insinuated my raised bed would only generate more work and wasn't worth it. It kinda' hurt.

Lots of encouragement to you from all of us here. Tell your friend that thousands of gardeners grow in raised beds with phenomenal results! Many can't garden without them. ;) While as the others have explained, you won't be making "soil", you will be making a great growing mix for your vegetables.

Good luck and enjoy the process.

Dave

If I understand your post correctly, you don't seem to be using any natural soil, just what any earthworms and other soil fauna bring up.

As Patrick pointed out, true "soil" is a collection of minerals, worn down rocks. I would add a big bag (100lbs or so) of sand, and a large bag (20 lbs) of Jonny Cat cat litter (new, not used) and a small bag (nursery size) of a rock phosphate. These would add some nutrients* that won't be found in most composts, add texture to your soil, give the earthworms some grit so they don't have to run down into the natural soil to get it, and neither one of them will burn anything at all. And they don't decompose appreciably, so they will be adding some non-disappearing bulk to your beds.

And if you happen to have to dig out some of your natural soil (any kind) from another project (small pond, fenceposts, etc), collect the top 7" or so and sift it a bit (at least pick out the rocks) and add it to the bed. This will add some soil microbes, who will be thrilled with the new food sources, and will multiply.

*Sand will add silica. Science hasn't figured out a way to measure it yet, but it is a viable nutrient.

*Jonny Cat's main ingredient is a clay called Bentonite. Clay colloids (the smallest part of the clay) attract and hold soil nutrients. The other kind of colloid is from humus, and you need both for good soil. (Not all cat litters are made from Bentonite, but Scoop Away, EverClean & Fresh Step are others with Bentonite - DO NOT using clumping litters.)

*Rock phosphate is a natural mineral made up of rock dust.

Sue

There are a lot of ways to "make" soil. I found a site where a gardener makes an organic bed by starting with a rectangle of bales of hay, and then he fills it with all sorts of compost, including a huge lot of mushroom compost. He provides detailed instructions plus photos of every step. I particularly liked the photos of all the mouth watering veggies he harvested from this relatively small bed. It really is worth a look. The point is, you don't have to start with bales of hay. You can just follow some or all of what he used for the center bit and still have a working garden. And forget about that negative woman and all her negative energy. You don't need her. Gardening is WONDERFUL for lots of great reasons: good exercise, good community of people to meet, terrific fresh food to eat -- what could be better? I just don't understand negative people. When someone says they want to do something and it's something I have no interest in, my response is: "Good for you!" We can't all be alike. What a boring world it would be if we were all interested in the same things. Anyway, tune her out, and happy gardening! MacThayer

Wow, you all know your stuff!--Thanks! I will definitely consider growing a green manure crop and will also read more about lasagna beds.

I didn't even think about the missing minerals and sand, so I'll definitely add the rock phosphate, sand, and clay.--I've used Johnny Cat kitty litter in a water garden container before, so I'm familiar it.

I agree gardening is good for you and I love being outside. I just can't get enough of working in the garden, but I also know it's not everyone's cup of tea.

Thanks again!

I just wanted to follow up on my post and say that I've used almost every suggestion each of you gave me to make this soil. I made a lasagna bed of leaf mold, coffee grounds, and well-composted manure and then added granite sand, rock phosphate, and a little bit of Johnny Cat litter. I've placed this in an a 3' x 6' area made with cinder blocks to make a raised bed.

One of the people I work with also gave me a big bucket of old soybeans and said that while the germination rate would not be 100% because the soybeans were so old that some would still sprout. I plan to use these soybeans as my green manure crop.

My cost to make this soil so far is about $15.00, which is pretty inexpensive compared to having soil trucked in.
I won't use this bed for my veggies till the fall.

Thanks again!