The "books" say to plant certified seed potatoes but I had such good luck last fall planting grocery store potatoes I'm going to try again this spring. I got ten pounds of "Butter Golds" from Walmart. These are the ones I selected to plant. I should have put something in the picture for scale but they range from egg size to tennis ball size. These are the culls that we will eat. I need twenty seed pieces, should I plant the ones I selected to plant whole or should I cut them? Should I have chosen the bigger potatoes to plant and cut them into 2-3 pieces?