I JUST built my raised beds (and am still working on getting them to 100%.. I still gotta do the trellises) and I got my dirt from a local mulch/landscape supply company. Cost just under 500 for 9 cubic yards delivered. It was called Premium Garden Mix and is a mixture of manure, compost, sand, and topsoil.

Unless you are dealing with an extremely impoverished sand or 100% clay or similar severe situation, it isn't necessary to go to the expense of importing all the growing soil. Most products sold for that purpose are not good bargains.

If you have an average soil to start with, cover it now as per your plan, to loosen it up and rot out any existing sod or cover. Anywhere in the humid east one can't go wrong with an application of dolomitic or hi-calcium lime. The very best thing you can spend money on is a bag of azomite. Their website has a list of dealers, if there isn't one within driving distance you can order it online. That will do far more in the long run than any amount of bought soil.

You'll get many different answers to this question. one need only browse all the previous discussions about it to see that.

So my personal recipe is 50% quality soil - your's may or may not be fine (no way to know) - preferably with some clay in it for some water retention, 25% good quality compost, and the remaining 20-25%in well-aged composted manure with some dolomite lime mixed in if needed to balance the pH.

I have also added peat depending on the pH test results and/or bags of soil-less potting mixes as my native soil is very alkaline.

The important factor in my mind is the size of the raised bed. Is it 2x4' or 4x8' for example?

The smaller the bed the more it becomes like a big container and dirt just doesn't work well in containers. It compacts and drains poorly. That is why the Mel's mix recommended by Sq. Foot gardening works or the 5-1-1 mix discussed over on the Container gardening forum works so well. Either way small beds need soil-less mixes only IMO. Large raised beds don't develop the "container problems" that small beds do so they can handle dirt-based mix.

Dave

If you are just putting raised beds in for the first time, and unless you have a mountain of dirt available, you have to import soil. When I put mine in I had garden mix delivered that was 1/3 topsoil and 2/3 mushroom compost. I have been very happy with it!

I get mine from the landfill, but ours is a very organic county and even the landfill garden mix is certified organic. Apparently you can't trust all of them to be great. In the past I've bought from a landscape supply place to fill new beds. Be sure to tell them it's for a vege garden.
After that I top with my own compost once a year. Nancy

What you should add depends on the soil you are starting with unless you intend to build it up 12" above the existing soil level.

My recipe for clay loams is adding 4 inches of peat moss and 3 inches of med/coarse sand and then mixing all that well into 7 inches of the existing soil... it makes a great soil for me. Some soils could use some lime [not all] and some mineral additive like Azomite.

your local hardscape/landscape supply companies sell it by the yard and can deliver. Way more cost effective than buying bags.

Here many sell a "planters' mix" of 50% screened topsoil and 50% finished compost. I agree mixing azomite in can't hurt and will only help.

"The very best thing you can spend money on is a bag of azomite. "

That's very expensive stuff per volume, and it would be last on my list. Until you have a soil analysis, you have no idea whether your soil needs any micro-nutrient supplements - and many soils in the East need none or very little. Your soil is already mostly ground up rock. - why do you need more? What we've got here is another Internet gardening fad.

And of course, if you're going to build a new raised bed, they the 'raised' part has to come from somewhere, so new material is needed to fill that volume of space. You either have to dig up another part of your yard, or bring it in from somewhere else. Just covering grass with cardboard doesn't make raised bed.

jonfrum, What soil test shows how much scandium, yttrium, iodine, strontion, cobalt, and many other micros are there for less than a hefty price? The whole idea is insurance as crop raising and centuries of leaching take their toll.

"The very best thing you can spend money on is a bag of azomite. "

"That's very expensive stuff per volume, and it would be last on my list."

While it is true It is good to not add something unless it is needed, it could be needed if your soil really is lacking minerals. There are many that use this "azomite". I never heard of it, but I just read it is used for soils that have been demineralized. It says there is 70 trace elements in it. I am not sure if those same elements can be found in just crop residue and horse manure and composted leaves which is about all I use for organic matter the rest of the nutritional needs are filled with synthetic fertilizer for my garden.

These minerals are said to be needed elements. If they are lacking then it needs to be added one way or another.

This is great info here-

"Justus von Liebig, the German chemist who became known as the âÂÂFather of Fertilizerâ (1803 - 1873) made major contributions to agricultural and biological chemistry by developing the Law of the Minimum. AzomiteâÂÂs primary nutritional function can be explained through LiebegâÂÂs Law. The Law states that plant growth is determined by the scarcest âÂÂlimitingâ nutrient. If one of the many essential trace elements is deficient in the soil, the yield and immune function of its plant life will be affected; therefore supplementation with the totality of the required nutrients supports optimum growth."

Source: http://en.wikipedia.org/wiki/Azomite

Here in socal, my native soil is decomposed granite, so adding granite dust as many recommend seems pointless.

The soil is naturally mineral rich. I read one report that said you pretty much just need to add nitrogen here.

I'm sure there can be deficiencies and amendments that will optimize fertility, but mostly I am just interested in adding organic matter and soil biota.

I figure organic matter has most of the minerals necessary for plant life. Also, some plants, like comfrey, operate as dynamic accumulators - mining minerals from deep in the soil and bringing to surface where they can be composted. Trees have deep root systems and so I am always composting leaves and wood chips.

My reason for adding some micro minerals is twofold. First it likely does help plants and trees to grow better. The second reason is for my health. Perhaps some of those micros are not essential for plant growth, but yttrium, vanadium, scandium, strontium, cobalt, iodine, and perhaps many others are helpful for optimum human health...something to think about beyond our nose.

we use anything that is available and economical, mushroom compost was our preferred for years but now greedy farmers who used to have to pay to get rid of it want too much.

this time we have lots of top soil from our building site, great loamy/clayey red or brown, very fertile naturally.

this time also raised beds using full width sheets of roofing corrugated, had lots of small logs and branches of all sizes so used hegelkultur idea and piled dirt on top. all well mulched and now well watered with app' 3/4 of a meter of rainfall in the past month.

Here is a link that might be useful: lens bale garden

this pic is that last pic now

len

When I fill raised beds, I use the finished compost that can be purchased from our city landfill. It is so cheap, almost free, and of good quality.

The trick, is finding friends who will lend me a pick up truck so I can bring it home.

Actually, Jon, east coast soils are famously leached. This is why liming is so common and always has some immediate effect. Boron is usually completely absent, Sulphur very low, sodium low, etc. If it is a highly leachable element it will be low or absent depending on how sandy the soil is.

I mixed azomite in with dried chicken manure on my corn crop at planting time last season and the plants couldn't be stopped by drought or insects, with no further fertilizing, in light soil where typically a crop would run out of health around waist high.

what kind of soil is best to use?
===========================

Best? How much money you got? :-) Some of the premium stuff out there (Roots, Foxfarm, Canna etc.) can go for $10 a cubic foot.

I have had good results in my raised beds with aged horse manure, peat moss, perlite & compost.