By Len Maniace

While thousands flocked to see the cherry blossoms in Washington, D.C., this past weekend, a secret garden grew deep underground in that city’s Metro.

We found the garden at the Metro Center subway station as we headed for the Tidal Basin to see said cherry blossoms. And there the mystery plants were: a mass of green, with tiny leaves poking through gratings which  protect some of the station’s fluorescent lighting.

So what’s going here? Is it an environmental sustainability project to provide fresh oxygen to Metro riders? Or maybe an outdoorsy decorating touch to soften the austere concrete-encased stations?

We leaned to a third possibility: that seeds had found their way to the bottom of the lighting trench and sprouted in the dampness there. The last explanation also seemed the most satisfying. Improvising on meager resources, nature was still thriving and pumping oxygen to riders while improving the station’s looks. Granted the amount of oxygen was small and most commuters might not notice the aesthetic improvement.

We soon learned the secret garden was not completely a secret. The Washington Post in 2006 noted the presence of Adiantum capillus-veneris, the common maidenhair fern, at the Woodley Park-Zoo/Adams Morgan stop, several stations from Metro Center. In 2011 the fern, which reproduces by tiny spores, which are even smaller than seeds, was found growing in Metro’s Tenleytown station by DC’s WJLA television. The next day Metro’s operator, the Washington Metropolitan Area Transit Authority, reported the plants also at the Cleveland Park and Van Ness stations, in addition to Woodley Park.

D.C. transit officials, however, shared none of the Post’s or WJLA’s enthusiasm for the indomitability of nature. The plants were bad for Metro, a sign of water, which can cause corrosion, a spokesman said. As a result Metro employees remove the plants as they make repairs though the system.

Those officials may be fighting a losing battle, however. Spores are tiny and are easily spread by the breezes created by subway cars. Furthermore, as long as water is subject to gravity, some will seep into tunnels – the New York’s subway stations are leaky examples. And as far as we know, D.C. transit officials have no plans to turn out the lights.