Continue to roll the dowel to within 3 inches of the end of the paper, then apply more paste in a zigzag pattern to this remaining area and finish rolling. Remove the dowel and allow the paper to dry overnight. The next day, when the paper is dry, cut the tube into 3-inch lengths.
When you're ready to start sowing, stand the open-ended cylinders upright inside a planting tray or flat, fill each with seed-starting mix, then plant your seeds. When it's time to transplant, place the pots right in the garden—the paper will decompose. (Be sure to cover the entire paper pot with soil so that the paper doesn't act as a wick, drawing moisture away from the seedling roots.)
It's easy to make your own biodegradable seedling pots. Simply spread open a standard sheet of black-and-white newspaper, then lay a 1¼ -inch-diameter dowel along one edge of the paper. Roll the paper and dowel one turn, then dab a small amount of flour-and-water paste on the rolled portion of the paper.