Sprouter is in a few dictionaries. Merriam-Webster says it is "a device for germinating grains (such as oats) for feeding livestock". But most of the contemporary usage occurrences I found are more related to a sense given by Wiktionary: "A small container for growing sprouting plants such as bean sprouts". In other words, a domestic gadget for growing plants to include in meals for humans.
I'll add it as a rare word.
