May 1, 2016 | Anne Craig

Rooftop gardens have been around at least since 6,000 B.C. and thrive all over the world. The benefits of growing in the sky for city dwellers are many: better air, cooler buildings, and the intangible but potent psychological boost of having green space as close as the last stop on the elevator.

And as the urban agriculture movement ramps up, urban farmers are increasingly looking upward for new spaces to grow. City land, after all, is notoriously expensive.

But there’s a steep learning curve involved in creating a viable rooftop farm any bigger than a few potted tomato plants or herbs.

“You’re looking at the liability and insurance risk of having people on a rooftop, and then you’ve got to make sure it’s structurally sound enough to withstand the extra soil weight for production,” Angie Mason, director of urban ag for the Chicago Botanic Garden, told NPR. “And you’ve got to make sure that you’re training people so that they aren’t compromising the rooftop membrane.”

To the rescue comes Annie Novak, a farmer, writer, educator, chef and Wendell Berry fan who has devoted her professional life to improving food systems. Her endeavors include founding and directing the farm-to-fork educational organization Growing Chefs, managing the Edible Academy at the New York Botanical Gardens, and co-founding and nurturing the Eagle Street Rooftop Farm in Greenpoint, Brooklyn, a 6,000-foot organic vegetable garden atop a three-story building.

Her new book, The Rooftop Growing Guide: How to Transform Your Roof into a Garden or Farm, (Ten Speed Press, 2016) addresses all the issues mentioned by Mason and a few more. Novak’s passion and encyclopedic command of best practices, not to mention her graceful prose, make for a work that’s both utilitarian and highly readable.

Novak’s currently on tour with the book, but we caught up with her and asked a couple of questions.

Seedstock: In the introduction to your book, you say that when you first heard of the whole rooftop farming concept, it seemed a bit nuts to you. Do you still feel the same way today?

Annie Novak: Rooftop gardening is a long-time historical practice with a great precedent of success. My initial concern, coming from a background in ground-level for-profit farming and vegetable gardening, was that for-profit farming could succeed in this challenging growing environment. The start-up cost of rooftop farming (no matter the model: greenhouse, green roof, or container gardening) is still a challenge, given that growing vegetables typically has a slow and low-profit margin. We’re still a young industry, and I think we’re still proving that this narrow aspect of the value of rooftop farming works and has longevity.

That said, it’s vitally important to recognize that the work that I do and the objectives that I care about in this work extend past proving a viable business model. I have never been skeptical about the need for more green spaces, and the value of growing local food systems.

SS: You mention that rooftop gardens are sometimes subject to bureaucratic red tape that can be “worse than the stairs.” What needs to change with respect to policy for rooftop farming to succeed in cities across the country?

AN: City policy around rooftop use, generally speaking, is there for the safety of the building, the building inhabitants, and the people up on the rooftop. If your municipality dictates a certain parapet height, access and egress, and fire code for use of your rooftop – those rules are important to adhere to.

Generally speaking, we’d see more rooftop farming nation-wide if incentives existed to support it. Many cities, New York included, went through boom periods in green roof projects when monies were budgeted for supporting projects that focused on stormwater management. Another option is to mandate green roof installations. In some cities, for example, new developments above a certain size must include a green roof or pay a tax on the per-square-foot of rooftop.

It’s important to clarify that the benefits of rooftop farming vary depending on the system used. Greenhouses, green roofs and container gardens all support plants, but differ in the environmental, economic and social benefits they provide. Because green roofs help with storm water management, and greenhouse and container gardens do not, they quality for the types of abatements described here.

SS: Is the amount of rooftop green space in NYC still increasing?

AN: New York City continues to develop far more standard rooftops than green roofs. However, there is certainly an increase in projects of all shapes and sizes within urban agriculture as a whole. It’s a very exciting time to be a green thumb.

That said, there is enormous room for improvement. The notoriety of Eagle Street Rooftop Farm and the popularity of large-scale projects like the High Line (a public-access rooftop garden in New York City’s Meatpacking neighborhood) is great, but greater still would be to hear that New York City’s Community Supported Agriculture programs with local farmers were selling out, that green roof installations were mandatory, and that the municipal composting test-run was being rolled out city-wide.

I’m an optimist by nature, but that does not preclude giving up on reminding people that we can always live better and more gently, both in New York City and elsewhere.