Where to buy Bulk Topsoil for Edibles ?
Topsoil is mostly just mineral. You have that already.
If you want to improve your soil for growing vegetables, we'd suggest adding organic material to your soil with things such as aged manure, compost, dried, crushed leaves saved from fall, etc.
It is more expensive, but is the material that will improve soil texture and beneficial microbial action.
Leaf Gro is a composted product made near you in Maryland. It is available in bulk and bags. If you do a Google search, you can find a list of retailers that carry and/or deliver it.
Just fyi, from our Master Gardener manual:
"...if your soil is of poor quality, new garden areas may need 4-8 inches of organic matter the first year or two. Plant roots, spent plants, cover crops, leaves, grass clippings, animal manure and store bought compost can all be used...aged animal manure should comprise no more than 25% of the total organic matter applied in any one year. The best option is to add compost to the soil. After a few years of large additions you can decrease to 1-2" each year.
It takes 3 cubic yards of compost to cover 1,000 sf to a depth of one inch.
The goal is to have organic matter comprise 25-30% of the top 8" of soil by volume."