Check with your local university extension service; they should be able to do this for you at minimal cost. Follow the instructions on their form carefully. This usually involves digging more than 6 inches deep in several spots, mixing the soil together, letting it dry, and then mailing it along with a form they provide. There may be a small fee for this service (it cost me $12).
They will test the soil and create a report telling you what type of soil amendments you need to grow vegetables, but even more important, if there is too much lead in your soil to even make vegetable growing safe (and if your children may need to be tested).
Much to our surprise, our soil has quite a high percentage of lead, so we are growing flowers in that bed (covered with mulch, per their instructions) and growing veggies in containers instead. For such a small fee, we found this information to be priceless.
By Natasha from Boston
