Sturdy orange rinds work like peat pots!
Just cut the fruit in half to make juice, and then scoop out any remaining pulp. Put the hollowed halves in a paper bag to dry for a few days in a cool, dark spot. Then they’re ready to fill them with potting mix and plant up with seeds, such as the cosmos (Cosmos spp.) here. When seedlings are ready to transplant, just gently loosen and remove the clump of soil.