This story was first published by Ensia.

Frank Morton has been breeding lettuce since the 1980s. His company offers 114 varieties, among them Outredgeous, which last year became the first plant that NASA astronauts grew and ate in space.

For nearly 20 years, Morton’s work was limited only by his imagination and by how many kinds of lettuce he could get his hands on.

But in the early 2000s, he started noticing more lettuces were patented, meaning he would not be able to use them for breeding. The patents weren’t just for types of lettuce, but specific traits such as resistance to a disease, a particular shade of red or green, or curliness of the leaf.

Such patents have increased in the years since, and are encroaching on a growing range of crops, from corn to carrots — a trend that has plant breeders, environmentalists and food security experts concerned about the future of food production.

A determined fellow dedicated to the millennia-old tradition of plant breeding, Morton still breeds lettuce — it just takes longer, because more restrictions make it harder for him to do his work.

"It’s just a rock in the river and I’m floating around it. That’s basically what we have to do, but it breaks the breeding tradition," he said.

"I think these lettuce patents are overreaching and if they [were to hold up in court], nobody can breed a new lettuce anymore because all the traits have been claimed." He continues to work with what is available, breeding for traits he desires while being extra careful to avoid any material restricted by intellectual property rights. He also has joined a movement that is growing in the U.S. and around the world: "open source" breeding.