When we were living in California, Marina and I found some sorrel plants at our neighborhood Lowe's hardware store, in the garden section. Returning back to Iowa, I had hoped to get some more sorrel plants, but was unable to find them. I finally found them online at Richters (
www.richters.com).
Service was so-so. They didn't take my order initially, because it was not during the growing season. Finally, after repeated calling, they got my order sent out. On the plus side, the seedlings arrived in a very healthy condition.
Sorrel is often used by Ukrainian ladies in some sort of borscht. They harvest it in the woods, just like mushrooms. Oftentimes, while riding from Kiev to Zhitomir, I'd see people alongside the highway, selling batches of sorrel they had harvested in the woods. It is a well known and popular herb over there.
If you have a Ukrainian lady over here, you might want to surprise her with an order of sorrel plants. We grow ours in a window box all year around. It seems to grow best in indirect sunlight with damp ground. One warning, however. It seems a lot of insects in Iowa seem to find sorrel as tasty as we do. We lost an entire batch, due to an infestation of japanese beetles. Nowadays, our sorrel is inside. In California, we didn't have this problem.