There's many other aspects to rearing moths (or butterflies), and the only limit is the amount of time and interest you have in it! As for ME, I have a greenhouse - thus assuring me of "greenery" year 'round, plus most of my half-acre yard is pretty much filled to to capacity with plants! These are in pots....... and many are taller than I am, and their height is limited to the height of the screen room I rear the caterpillars in (For you lacking a screen room/porch, a screen tent works perfect!).
Many of the plants have been in pots now for over ten years, and I "Bonsai" them every other year or so to keep them growing well, and the plants THEMSELVES have become quite a hobby in itself!
Some have asked me "Why moths and not butterflies?". Well both are easy to raise, and maybe in time there'll be "Joe's Butterfly Page" - explaining how a simple setup (like a screen tent), containing both potted nectar plants for the adults, plus the foodplant for the larvae, which the female will lay her eggs on, as well as a list of butterflies that fly well in captivity (and which ones don't!), and maybe there'll even be a section showing the ease of transplanting/growing the plants, and the preferred foodplants for certain butterflies, as well as the best "everblooming" nectar - like Pentas for example - but who wants to go through all THAT when all it takes is a paper sack to toss the female moth into instead?!