I came up with this. Paper seedling tubes. Made from old pieces of A4 paper [old bills, pamphlets, etc], they’ll biodegrade quicker than the toilet tubes once placed in the ground. And you don’t need glue or tape to hold them together.
They’re a little fiddly to make at first but once you get the hang of, they’re quite easy.Fold a piece of A4 paper in half widthways. Unfold and fold in half lengthways. Leave folded lengthways.
Fold from the point on the centre crease where the halfway crease is, diagonally from corner to corner. Unfold the last fold.
From the end of the centre crease, fold the paper inside itself on the diagonal fold line. What you should have is a piece of paper with a taper starting from the centre of the length going to a point at the other end.
Now roll the paper into a cylinder shape. Then insert the point between the folds and coil it inside until none of the tapered section is showing. It takes a bit of practice to get it to stay there, but it will.
I have found you don’t need bottoms in the as long as you pack them well with soil and place them in a tray [mine are sitting in a cardboard tray we bought croissants in].