I hate plastic; I might not have enough plastic pots anyway; they wouldn´t be deep cylinders. So I tried making some pots out of newspaper to pot up my tomatoes into.
I rolled them around a bottle (half-sheet each), crunched in the paper on the bottom, slid the cylinder off the bottle, and then turned over the half inch at the “brim” to the outside. That´s what keeps them rolled. Takes about 20 seconds each. They kind of try to unroll anyway, but they hold together great once a little soil goes in them.
It remains to be seen how well they hold together once they have a plant in them and get watered. But if all goes well, I can write the variety right on the paper with a Sharpie, and I suppose I can put them directly in the ground as is (that´s a lot of newspaer ink, though).
Ready to accept transplants. We shall see.