I don't know what everyone else uses but, I used E6000. My flowers held up in 65 mile an hour winds with rain that came with it. I don't drill my pieces I stack two at a time and glue them, kind of like an assembly line that can take a couple of days. Stack and glue, dry for 24 hours, put next piece on and dry for 24 hours. If you use 4 pieces for instance, I stack 2 at a time then stack those together. I used a hockey puck that I drilled to the size of the electric fence post that I can pound into the ground. I hope this helps
sorry most of these are in boxes for transport to a craft show.
Save the planet, it's the only one with chocolate.