The first thing would be to get a soil test done on your back fill to see what's in it. After you screen out the rocks, that dirt can probably still be the basis for building your bed soil. If it is like most back fill in Maryland, you most likely have red clay that unaltered would pack down into hard pan pretty easily and it is probably sterile of earthworms right now.

If that is true, what you need to add is about 1/3 compost and maybe 1/4 sand or peat to lighten the soil. If it is not pure clay, you may only need to add the compost.

Depending on what you have available, you could always till in a whole lot of chopped up leaves, rake out the rocks that are on top and top with mulch that you will till in later on and let nature do the composting work in place and the worms take the organic matter down rather than dig out and replace.

It depends on how much muscle and money you have available.

Hi, I recommend you Google "double digging" or "double dig." Both will pull up the many articles.

I've done both, double dug (I guess that's the correct tense) and spot amendments where I planted in my shade gardens. I believe the sun gardens really did benefit, while the shade gardens naturally have an abundance of humus and other organic contributors. If you do send in soil samples, be sure to send in several samples or make sure you don't assume the results will be the same out in the yard as the results up close to the house. One piece of property can have several different environments, each with their own requirements.

I buy bagged Shenandoah Top Soil from Rels in Olney. They will deliver in bags or you can get them to deliver in bulk by the cubic yard. The bulk topsoil is pretty good and even better when mixed 50/50 with Leafgrow, which they will do for you as bulk.

Adding as much MANURE as you can afford is helpful too. I add it as a 2 inch layer at the bottom of the bed, and the worms eventually distribute it. I get sheep manure from a lady in Howard County, but if you noodle around on the Internet, you can find other sources for horse or sheep manure. The bagged cow manure from Home Despot or whatever seems to me to be "dead" and worthless.

I completely agree about anything of the bagged manure, humus or the cheap top soil at Lowes or Home Depot. Don't bother, you might as well be putting dead clay down no matter how they label it.

I've used Black Kow with good results:
http://www.homedepot.com/p/Black-Kow-50-lb-Composted-Cow-Manure-BLKCOW/202287053

I know about digging in hard soil. You want to get a solid metal "leverage fork". Best tool ever since the shovel! I can't find a source for it (it was a gift 20 years ago) but you can see a picture of it on my blog at http://cavebearslair.blogspot.com/2013/05/good-yardwork-day-yesterday-2.html.

Its the best tool I have. If you can find it, use it!.

I used it for 3 hours yesterday ripping out vine roots from soil I was moving to a new bed. When you look at it, you will see that there is space to put your foot in to press down. The U-Bar lets you bend the handle down and lift the soil up no matter what is in the soil.

THEN mix your your dug-up soil with some compost or AGED manure.