This is an herb spiral, in which you plant drought hardy plants at the top and water-thirsty plants at the bottom. By adding wood, it mimics hugelkultur, in which buried wood adds nutrients and reserves water. -Grow Food Not Lawns
❧ Old Ways Handy Farm Devices - Cobleigh - chapter Perhaps something like this can be rigged to keep rainwater cistern clean. Incredibly clever auto-leveling fill to keep both barrels filling appropriately.