I have a worm habitat called a "worm inn". It is a clever device that both grows worms and provides castings from veggie waste, coffee grounds, shredded paper and cardboard, just about anything organic that is not an animal byproduct.
I use red wigglers because they were cheap and I could order them online.
One of the advantages is you are supposed to water the bin until there is a slight runoff. That runoff is a killer base for a tea. The plants absolutely love it. They also love the castings themselves.
Good stuff, and completely free once you get past the initial set up costs. The worms eat your garbage and turn it into black gold. What could be better?