Question
I live in Ohio, south of Cleveland where we are known for our clay soils.  I recently sold my house, (where I had a small compost pile) to an apartment.  I have some small beds where I can plant flowers but the soil needs help.  I moved here in August and couldn't get the shovel in much deeper than about 3 - 4 inches and it felt like I was hitting solid rock.  This spring probably because of snow and rain over the winter I can at least get the shovel in the ground, but it is wet and sticky right now.  I need to add something to improve it and there are so many different choices in the garden centers.  Among other things there is Peat moss, some black stuff called humus, something called Planting mix, which I have used to mix in holes when planting annuals etc.  It is 75% top soil, 15% compost, and 10% peat moss. I also saw something that had cow manure in it, which might be the closest to compost that I've seen.  I got talked into buying Miracle Grow Garden Soil that has fertilizer in it, but haven't done anything with it yet. I can't see that adding more soil to clay soil is going to improve it as much as compost would.  I don't seem to be able to find regular compost that you can buy, unless it was the stuff with cow manure added.  The community where I lived before had a composting facility and you were allowed a certain amount free each year.  What is the best thing to use?  I have to pull back the mulch that is on top of the dirt, do whatever, and then replace it, so it will be kind of a hassle to do a lot of digging. Plus I'm a 73 old lady - active though.
Thanks, June

Answer
Hi June, First - loosening the clay is the most important thing to do, what you put in it to help keep it loose, is not as important.  I like finely ground (1/4") pine bark.  It's cheap and works well.  If you can't find that, the "planting mix" sounds ok but I'm always curious to see what they call "top soil".  Often it is bark, leaf mold and sand, sometimes it's real top soil (clay).  I strive for something coarse as the primary soil amendment.  Then adding a little manure, humus or peat is fine.  I'm not a big fan of peat moss.  
Don't over-improve your soil.  Adding 30% - 40% organic material should be max.  This will separate your soil and add depth which will improve your surface drainage.  
The soil needs to be loosened well, so you may need to have this done for you.  Jim