The challenge of space gardening: One giant 'leaf' for mankind

• News & Highlights

It's not easy having a green thumb in space.

Without gravity, seeds can float away. Water doesn't pour, but globs up and may drown the roots. And artificial lights and fans must be rigged just right to replicate the sun and wind.

But NASA has decided that gardening in space will be crucial for the next generation of explorers, who need to feed themselves on missions to the Moon or Mars that may last months or years.

Necessary nutrients, like vitamins C and K, break down over time in freeze-dried foods. Without them, astronauts are increasingly vulnerable to infections, poor blood clotting, cancer and heart disease.

So the US space agency has turned to professional botanists and novice gardeners—high school students, in fact—to help them practice.

"There are tens of thousands of edible plants on Earth that would presumably be useful, and it becomes a big problem to choose which of those plants are the best for producing food for astronauts," explained Carl Lewis, director of the Fairchild Tropical Botanic Garden, which is leading the effort.