A greenhouse presents a wide array of opportunities for making money, even on a small scale. Products can be harvested or made from your freshly sourced produce. This includes jams, jellies, pickled vegetables, nut butters, frozen pies, ciders, etc. If branded and approved, these products can even appear on some store's shelves.
The greenhouse itself can also provide some income, if utlized as a store, or by offering classes, experiences, etc. to the public. Here, seeds can be sold, alongside plant starters, growing kits, gardening supplies, or fully matured plants like fruiting trees, flowers, or shrubs.