A “Moon Plant,” more commonly known as a Moon Tree, is a tree that grew from a seed that traveled beyond Earth’s orbit and circled the Moon. This designation means its genetic beginnings were exposed to the deep space environment, not that the plant grew on the lunar surface. The story of these trees is a blend of space exploration and botany, originating with an experiment to study the biological effects of space travel on plant material. These living artifacts serve as tangible reminders of the ambitious Apollo program and the intersection of scientific curiosity with the natural world.
The Journey of the Seeds Aboard Apollo 14
The historical context for the Moon Trees began with NASA’s Apollo 14 mission, which launched on January 31, 1971. Command Module Pilot Stuart Roosa, a former smokejumper with the U.S. Forest Service, carried the seeds in a small canister in his personal kit. The experiment was proposed by Forest Service Chief Ed Cliff, who knew Roosa and saw an opportunity for a joint NASA-Forest Service project.
The primary objective was to observe the impact of the space environment—including microgravity and cosmic radiation—on seed viability and growth upon returning to Earth. Five different species were selected for their wide geographical distribution and commercial value:
- Loblolly pine
- Sycamore
- Sweetgum
- Redwood
- Douglas fir
Roosa carried approximately 400 to 500 seeds.
While Commander Alan Shepard and Lunar Module Pilot Edgar Mitchell walked on the lunar surface, Roosa orbited the Moon 34 times. The seeds remained sealed in the command module, Kitty Hawk, exposing them to the deep space environment. They were stored in small plastic bags inside a metal cannister for protection. This scientific payload was intended to provide data for the Forest Service’s research into seed genetics and space biology.
Post-Flight Growth and Botanical Observations
Upon the crew’s return to Earth, the seeds underwent a mandatory post-flight decontamination procedure. During this process, the sealed container burst open, scattering the seeds across the vacuum chamber floor. This incident raised immediate concerns about their viability, but the Forest Service collected the scattered lot and attempted germination.
The seeds were sent to two Forest Service research stations, one in Gulfport, Mississippi, and another in Placerville, California. Specialists began the delicate process of germination, and remarkably, a large number of the seeds survived the ordeal. Nearly all of them successfully germinated, though initial attempts at growing the saplings were hampered by inadequate facilities.
The core of the experiment involved planting the newly grown “Moon Tree” saplings alongside a control group from the same parent trees. Researchers monitored the growth, development, and health of both groups over several years. The scientific conclusion was definitive: exposure to the deep space environment had no detectable effect on the seeds. The Moon Trees grew identically to their Earth-bound counterparts, exhibiting no genetic mutations or abnormal growth patterns.
The Legacy of the Moon Trees
The successful seedlings, totaling around 450, were eventually distributed across the United States and internationally. They created a living monument to the Apollo program, with many planted in 1975 and 1976 as part of the nation’s Bicentennial celebration. These trees found homes at state capital grounds, universities, historical sites like Valley Forge, and the White House.
The distribution of the trees was not meticulously documented, and many were planted without permanent identifying markers. For decades, the locations of many original Moon Trees were lost. This prompted NASA scientist Dave Williams to create a database in 1996 to track the surviving specimens, locating over 100 of the original trees.
The legacy continues with “Second Generation Moon Trees,” grown from the seeds or cuttings of the original space-faring trees. This practice, championed by Roosa’s daughter through the Moon Tree Foundation, ensures the genetic line of the trees persists. The symbolic importance of these trees was recently reinforced when a new batch of seeds was carried around the Moon aboard the Artemis I mission.