Seedling pot made from an empty toilet paper roll. After germination, it can be buried directly in the garden bed as is; the roots will grow through the softened cardboard, and soil organisms will then consume it. Make sure to only use toilet paper rolls made from unchlorinated and unprinted cardboard.
edit: please check if recycling has a problem with chemicals or heavy metals in your country
PLEASE DONT EVER PUT RECYCLING-PAPER INTO SOIL!
There are a lot of bad chemicals in recycling-papers!
not in germany, there are not a "lot" of bad chemicals in recycling paper, since the limit values are very strict. however i don't know how other countries handle this. i will put an edit in the original post.
chemicals in tp are of course a big problem. tp isn't very hygienic anyway. we already decided to build in a bidet as a new project.