One of those teams, from Wageningen University in the Netherlands, previously tried growing food plants in simulations of both lunar and Martian soil. Although those tests proved unsuccessful, that wasn't the case the most recent time around.

The soil simulants were provided by NASA, with the moon soil actually coming from a desert in Arizona, and the Mars soil coming from a Hawaiian volcano. Previously, plants grown in nothing but these soils died. This time, however, fresh-cut grass was added to the growing medium. This helped the soil to retain water, while also acting as a form of fertilizer. 

As a result, the team successfully grew 10 crop species including tomato, rye, radish, pea, leek, spinach, garden rocket, cress, quinoa and chives. The amount of above-ground biomass grown in the Martian soil simulant was similar to that managed in regular potting compost used as a control, while the lunar soil simulant yielded about half as much biomass.