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
i recommend a worm composter. this way you would collect the rolls anyway (because worms like them) or working as an educator ;)
lemmy needs a remindme feature :D
"remindme" on The Discussion Forum Which Shall Not Be Named was just a bot account run by a third-party. The Fediverse not only has the same, but has several to pick from. (I say "the Fediverse" rather than "Lemmy" in particular because the first one that comes up in the autocomplete is actually a Mastodon account, @remindme@mstdn.social.)