If anyone works in or has family members who work in a restaurant, broccoli comes in wax saturated cardboard boxes. They are easy to spot, due to their dark color and end up in recycling dumpsters where they are considered contaminates by recycling plant operators. I cut them up with a utility knife into pieces about 3"x 4". Often when burning light weight wood like pallets, I don't even need kindling. Around 4 pieces of cardboard do the trick.