Updated

Transit officials in the nation’s capital have identified a grave new threat: A guy who plants flowers.

Henry Docter thought he was doing a good thing, beautifying the city he loves by planting flowers in forgotten flower boxes around the Dupont Circle Metro station in Washington, D.C. Then he received a cease-and-desist letter from Metro officials, threatening him with “arrest, fines and imprisonment,” if he dared continue his unauthorized botany.

“The typical response [should have been] a heartfelt thank you,” Docter, who calls himself the “Phantom Planter,” told FoxNews.com. “I never expected nor have I ever received such a letter.”

Metro officials told the Washington Post the warning was for Docter’s own good. After all, they said, the  flower boxes he sought to beautify are set along steep, cobblestone steps and Docter could fall while watering, weeding or otherwise tending to his flowers.

Docter, who claims to have planted 40,000 flower bulbs in public places around the world, believes he has the experience to safely continue his floral exploits. Planting flowers, he said, is “a joyous occasion.”

Metro officials did not respond to a request for comment.

Straphangers seem to be siding with Docter, especially given that the terrace garden at the Dupont Circle station was falling into disrepair.

“The terraced garden area was neglected and the flower planters were full of cigarette butts, shards of glass and other debris,” said Docter, who guesses he planted more than 1,000 flowers in the terrace garden in the spring.

Ironically, it was Docter’s own passion for planting that got him into trouble with Metro officials. He had sent a letter to a friend, asking them to find someone at Metro with “both a brain and a heart,” so he could get permission to continue caring for the flowers.

“Unfortunately, in addition to a brain and a heart, I should have also asked to speak with someone who had power and common sense,” Docter told FoxNews.com.

Docter is working to garner support for his cause through an online petition on Change.org. So far he has gathered over 2,000 signatures supporting his phantom flower planting. He also has a website dedicated to help get the word out about the flowers found at letmyflowersgrow.com.

Nicolette Kearney contributed to this report