Walipini, underground greenhouse, geothermal greenhouse

Permies planning thread for Montana Zone 3 tropical/perennial crops comparing walipini, geothermal, and hybrids; responders stress site-specificity (water table eliminates walipini; rocky ground hinders geothermal). OP wants Zone 8–11 crops (pineapple, banana, turmeric, citrus, aloe) in likely Montana Zone 3; open to rocket mass heater backup. Responder advises combination approaches are site-specific: high water table eliminates most walipini positives; rocky ground discourages deep geothermal digging; half-walipini with geothermal may work. Later posts discuss hybrid non-sunken builds for wheelchair access in Northern BC Zone 3. Mentions Greenhouse in the Snow (Zone 5a) as a reference point with uncertain Zone 3 transferability.

Evidence tier: forum. Planning discussion without completed build results from OP.

forum|candidate