Why are my vegetables not growing well in the elevated planter I created?

Question: I created an elevated vegetable planter in a metal trough on legs. I lined it with black landscape cloth. The bottom of the trough has many circular punched out holes for drainage. I put in a mixture of purchased Coast of Maine container (2 parts) and Coast of Maine lobster compost (1 part). I read more Why are my vegetables not growing well in the elevated planter I created?