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
How to turn tree stumps & logs into planters. Succulent gardens in hollowed out logs, and also in timber rounds, available from the Succulent Guy at the Byron Bay Beachside Market - Easter Saturday March.