Fish and eel waste were dug into the soil to improve fertility, before creating planting mounds 50cm wide. A bunch of corn seeds were sown close together in the centre. When they grew to about 15cm tall, bean and squash seeds were sown around the outside. The corn stalks provided poles on which the beans could climb, while the beans fixed atmospheric nitrogen and returned it to the soil. The squash, with their giant leaves, acted as a living mulch, reducing weed growth and soil evaporation. It’s a great companion-planting project to try yourself, and if want to try some other clever Aztec ideas in your garden, learn about them in Tino Carnevale’s story in the November issue. We also have features on how to grow beautiful plump eggplants and fragrant French tarragon this summer.