Trees with Edible Leaves: PAI’s latest publication

The Perennial Agriculture Institute is very pleased to present our latest publication: Trees with Edible Leaves. It provides an overview of a remarkable group of crops, with details on nutrition and cultivation techniques. Over 100 cultivated species are described in detail, for both cold and tropical climates.

Trees with Edible Leaves is available as a free download thanks to the generosity of Trees for Climate Health, an initiative of Jonas Philanthropies. Thanks also to Eric Toensmeier’s Patreon supporters, and our fiscal agent Interlace Commons. The publication is under Creative Commons BY-NC-ND 2.0, which means you may share it freely for noncommerical purposes, with attribution. A special thank you to contributing author and “roving reporter” Erica Klopf who traveled all over Florida to taste and propagate a great diversity of species to be found in the state’s many botanical gardens and other collections.

We are at work on a Spanish edition. Please contact us if you are interested in helping to translate it into additional languages, as a translator or funder. In the future we would like to offer further editions with greater detail including an inventory of promising non-cultivated species.

You can email us at perennialagricultureinstitute [at] with any comments or suggestions.

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Our new article on perennial staple crops

PAI is happy to announce that our newest article, “Perennial staple crops: Yields, distribution, and nutrition in the global food system” was published today in Frontiers in Sustainable Food Systems. Building on the information presented in PAI Director Eric Toensmeier’s book The Carbon Farming Solution, this peer-reviewed article by lead author Maayan Kreitzman provides, for the first time ever, peer-reviewed analysis of the yields, nutrition, carbon sequestration, and adoption potential of this important class of perennial crops.

Perennial staple crops at Las Cañadas in Mexico: macadamia, air potato, and the giant acorns of chicalaba (Quercus insignis).

our new publication on perennial vegetable nutrition

PAI is happy to announce our latest publication, a collaboration with six farms, gardens, and educational projects in Denmark, Sweden, and the US. We tested the nutrition of 14 species of cold-climate perennial vegetables, with a focus on species for which only incomplete data were available, or no data at all. This effort builds on PAI’s 2020 paper “Perennial vegetables: A neglected resource for biodiversity, carbon sequestration, and nutrition”. Thanks to our crowdsourced backers on who funded our research.

Testing nutrition of cold-hardy perennial vegetables: Fundraiser

PAI is proud to be working with a team of Swedish perennial vegetable experts on a project to test the nutrition of several important species. You may recall PAI’s paper last year which reviewed the existing literature on perennial vegetable nutrition and found that some perennials are among the world’s most nutritious crops when it comes to addressing the deficiencies that are impacting billions of people in both the Global South and North. We also learned that no data, or only very limited data, are available for many important perennial vegetable crops. This project aims to fill those gaps.

This kind of testing is quite expensive. The collaborative aims to raise $5,000 to test a wide range of nutrients on four crops: linden leaf (Tilia cordata), hosta shoots (Hosta sieboldii), Caucasian spinach (Hablitzia tamnoides), and scorzonera leaves (Scorzonera hispanica). All funds will go to testing and associated costs – our team are all volunteering our time.

Please visit our fundraising page at to learn more and to support our effort if you wish.

A new climate and agriculture publication from PAI Director Eric Toensmeier

Today Project Drawdown released a new publication, Farming Our Way Out Of the Climate Crisis, with PAI Director Eric Toensmeier as lead researcher. It addresses agriculture’s emissions contributions, strategies to reduce emissions from agriculture, and the potential for (and myths about) carbon sequestration.

Here’s a summary of some interesting insights – that every farmed part of the world has something to offer, though they are not equal in their potential impact. This figure is not included in the publication, but the issues noted in it are. Briefly: sandy soils store less organic carbon, but have a higher methane storage potential compared to clay soils. Wetlands hold (much) more soil organic carbon than uplands, but have a smaller methane sink compared to uplands. Drylands store less organic carbon, but more inorganic carbon. Tropical regions have more carbon in biomass and less in soils, with the reverse in colder climates. In all cases, methane sinks are very small.

The article can be downloaded here.