The city has agreed to allow a group of techno gardeners to build the Lowline – a subterranean park in an old Lower East Side trolley terminal.

The city’s first underground park is planned for the terminal under Delancey Street, which is visible from the Essex Street J/M platform.

Engineers plan to use solar technology to create a lush biosystem of greenery in the now dank and dark facility.

The Economic Development Corp. gave the go-ahead early Thursday, officials said, but the gardeners still need to procure an estimated $80 million in funds.

“For eighty years, this underground space has sat idle,” said Deputy Mayor Alicia Glen. “Now we’re putting it to use for the people of the Lower East Side and for all New Yorkers to enjoy. We can’t wait to see this experiment unfold.”

The city has not yet promised any funding to the project, which still needs to raise $10 million, and it still needs final environmental and city Council approval, said EDC officials.