Why we still make shoes out of trees
By the Allbirds materials team · November 2025
Six years ago we put a eucalyptus tree on a shoe and a lot of people told us it wouldn't hold up past the second wash. The Tree Runner is now in roughly four million closets, and the trees we source from in South Africa still grow on land that didn't need a single drop of irrigation.
That's not a flex. That's the whole point. Here's how the upper of every Tree shoe actually gets made — and why we'd rather lose a margin point than swap the fiber for something cheaper.
1. The tree comes first, the shoe comes fifth
Eucalyptus pulp gets spun into a yarn called TENCEL™ Lyocell. It uses 95% less water than conventional cotton, and the closed-loop process recycles 99% of the solvent. That's the part the certifications care about.
2. Why your foot doesn't sweat in it
Tree fiber is naturally moisture-wicking and runs about three degrees cooler than wool. That's the part your foot cares about on a 92° August commute.
3. The carbon number on the tongue
Every pair ships with its lifecycle CO₂e printed where the size tag used to be. The current Tree Runner sits at 7.1 kg — about half of an average sneaker. We publish the math; you can audit it.
Want a pair to try?
30-day wear test. Walk in them. Run in them. Wash them. If they're not the most comfortable shoe you own, send them back — we'll re-mill the wool and send the trees back to the soil.
