Maniac
Apolyton Sage
Two questions: 1) Why can't greenhouses be built on rocky terrain? Because it seems to me, like it should be physically possible to build a greenhouse anywhere on land. Or is it a strategic reason I don't see?
Hmm, I could allow greenhouses on rocky. It does fit in the Enclosed Biosphere theme of turning harsh and hostile terrain into something useful.
While, before Bioreactors, greenhouses seem clearly a worse choice to build on Rocky compared to mines and windmills, it could help to make researching Ultraponics more a valid choice besides Renewable Energy and Centauri Geology. Some yield improvement on a rocky plot is still better than none!