I was planning to grow some vegetables in this container somebody left in my backyard. its approximately 5 feet long, 8 inches wide, and 8 inches deep. I bought a 2 cubic feet Black Gold potting soil bag, which i discovered was a mistake. I took prestons_garden's advice and i'm going to mix the Black Gold soil with this pumice i bought on amazon (I tried going to several garden stores and all they carry is fine perlite) I feel like my soil is already compromised. Is there anything I can do to further amend this mixture? also another main question i have is, what can i grow in a container this shallow? should i just get deeper pots like the ones behind it and grow in those?