Cider House Farm Market, which is located near Zelionople. They have some "phat" asparagus and rhubarb. The owner used to be a grower herself but now stocks products from local producers. She has a cider press at her market and you can bring apples to be pressed in the fall! Cool. This could be a great place to visit for those who live nearby if you haven't been already.
Cherish Creamery was there as well with goat cheeses galore. They were offering free samples and selling lots of varieties.
Other vendors such as Edible Earth Farm (produce producer and CSA), Who Cooks for You Farm (produce producer and CSA) and Grow Pittsburgh had many seedlings. I hope you get a chance to visit and pick out something for someone or yourself.