This is a Speedling tray nestled into a green underplate that holds the styrofoam up off the bottom. This design feature allows the roots to be air-pruned and promotes sturdy seedlings. Another design feature is the shape of the planting hole. These are pyramidal with a hole in the bottom. Transplant shock is almost unheard off using these trays. The sustainable part of these is that the trays can be used repeatedly for many seasons.
Since it is March 1, even though Mother Nature is still giving us Winter, I am starting my tomatoes today. We will have over 30 varieties this year by the start of our season - July1.