Many of you have made these also.
I did this project with my son's second grade class---a great garden project for kids. The kids did 100% of the planting. My son's class has 12 students, so there were 4 students working on each one. It took us about 90 minutes. We made 3 total.
These just sold at our fund raising auction/gala for $1000 for the set.
Frames came from Flora Grubb gardens, and measure 20x20 inches each. I kept them flat in my heated greenhouse for 3 months before the auction. I also overseeded them with semps that had gone to seed from my yard.