Rootbuilder II pot
The University of Guam native plant nursery and Plant Extinction Prevention Program have been having success using Rootbuilder II pots. These containers allow good drainage and prevent roots from spiraling. They ship flat and are assembled on site with zip ties. Two or more containers can be zipped together to make a larger container. These pots are a product of Rootmaker (rootmaker.com) and may be available through other retailers.
University of Guam, Mangilao, Guam.