As I referenced previously, when considering the long term planetary outcomes of our food choices, there are real advantages to foods that come from or coexist with perennial ecosystems; ecosystems that are built around perennial plants. Eating grass-fed meat is a way of supporting the perennial pasture that the animal is raised on. Tree and bush fruits come back year after year. There are even a few (not many) vegetables that are perennial- you can read about them at this blog. Unfortunately, it seems this blogger ran into the realization that since there are only a few perennial veggies, there really wan't that much to write about. The blog seems to have lasted only a few months.
The real Holy Grail for permavorism, and I would argue for sustainable agriculture in general, would be a perennial grain. Throughout human history, grain has formed the backbone of nearly all regional cuisines. Currently all grain crops are annual plants, re-seeded year after year. Since the plant dies and reproduces each year, it does not have the same opportunity to extend vast, complex networks of roots into the soil as do perennial plants. The soil beneath is less stable, lacks the fullness of organic material that characterizes the soil that supports perennials, and does not hold onto and recycle minerals and water as well. This is a problem to the land and to the environment as a whole.
The Land Institute, under the leadership of agro-visionary and sustainable agriculture pioneer Wes Jackson, seeks to change that. Seeking to "develop an agricultural system with the ecological stability of the prairie and a grain yield comparable to that from annual crops", the land institute seeks to mimic the wisdom of natural ecosystems with productive food producing plants. Much of Jackson's vision is laid out in his books; New Roots for Agriculture and Becoming Native to this Place. The work of cross-breeding plants to create perennial, productive grain crops is laborious and time consuming, so the wait for a permanent agricultural grain crop must be a patient one.