In Puna, and other areas of Hawai'i that are dry, barren, and / or covered with lava, a method of farming called puhala was employed.
Hala (
Pandanus tectorius) was grown in places where there was nothing. Hala is were tough and resistant. It can be watered with sea water to keep it alive.
Once the hala plants were grown to size, they were chopped down and made into a pile. After the pile had decomposed a bit, holes were made and bananas, taro, and other plants were cultivated in the pile.
http://ntbg.org/plants/plant_d...
http://wildlifeofhawaii.com/fl...
