You gotta give it to Dickson Despommier—he’s certainly persistent. The professor of public health at Columbia University has been pushing the concept of vertical farming in cities for the past several years, and he made his pitch again in Sunday’s New York Times. He even tossed in a few stats on the economics of growing food in urban highrises to counter the arguments of skeptics. You can find my previous takes on vertical agriculture here,  here, and here.

It remains to be seen whether vertical farming in cities is feasible economically, but it’s sure inspiring a growing number of architects. You’ll find a thumbnail history of the sky farm, as well as 16 different designs, at Dornob. Two of my favorites—complete with stunning renderings—are Eric Ellingsen’s and Dickson Despommier’s Pyramid Farm, and Vincent Callebaut’s Dragonfly Farm.

So, how long do you think it’ll take for many of the American households growing their first food garden this year to decide a) it’s a lot more work than they bargained for, b) they’re losing the battle with cutworms and weevils, and c) they need help? Former NPR correspondent Ketzel Levine and other laid off garden scribes may want to steal a page (and a business plan) from the two women in Portland who launched Your Backyard Farmer, a sort of urban CSA, to transform small city lots strewn with last year’s toys, overgrown flower beds, and compacted grass into productive miniature farms.

After conferring with prospective clients about their needs and favorite veggies (there’s even a downloadable pdf on Your Backyard Farmer’s website with a list of edibles for families to choose from), the two build raised beds and healthy soil, plant, and make weekly trips to tend and harvest. Every week, clients come home to find a basket of freshly picked, organically grown produce waiting at their back door.

As CSAs go, the service isn’t cheap—planting and tending a garden capable of producing enough produce for a family of three reportedly cost $1,575 last year—but those wishing to economize can opt instead for hands-on lessons on running a backyard farm for about $100 a month.

According to the U.N., half the world’s population already lives in urban areas, and about 70 percent will be city dwellers by 2050. What kind of structures can accommodate all these people while promoting human and environmental health and creativity? An increasing number of architects are looking to plants to find solutions.

The population of tropical cities in particular is expected to skyrocket. Inspired by the densely layered life forms found in tropical rainforests, among the most biodiverse natural communities on the planet, TROPICOOL@KL envisions mushroom-like skyscrapers punctuating Kuala Lumpur’s skyline. These highrise structures, which look as much like the Coney Island Parachute Jump as they do mushrooms, mimic the five layers found in tropical rainforests: the overstory, the canopy, the understory, the shrub layer, and the forest floor. Solar panels in their circular tops provide energy, just like the photosynthesizing leaves that comprise a rainforest canopy. Scattered throughout the branches of the self-sustaining, off-the-grid skyscrapers are apartments modeled after vernacular Malaysian dwellings. 

Intended for Manhattan’s currently semi-industrial Hudson Yards area, which runs roughly from West 42nd Street south to West 30th Street and from Eighth Avenue west to the Hudson River, Eric Vergne’s unfortunately named Dystopian Farm is a skyscraper that combines spaces for housing, markets, and food production. Vergne says he modeled his design after the cellular structure of ferns, and that the building will use biomorphic systems such as aeroponics to meet the food demands of a growing urban population.

Although vertical farming in cities has inspired the design world, some skeptics have claimed it makes no sense financially because urban real estate is too expensive. Our current economic mess, however, just may create a window of opportunity for such visionary projects. In the words of Stanford economist Paul Romer, “a crisis is a terrible thing to waste.”

An edible rooftop garden prototype on a residential building in Los Angeles is planted with fruit trees, vines, herbs, and vegetables that will be tended and used by residents and the chefs at the well-known ground floor restaurant, Blue Velvet. 

You know the term “green” has become almost meaningless when Inhabitat extolls Europe’s lawn-lined railways as paragons of green design. Have they gone bonkers, or has Scotts become a major advertiser? Granted, the color green is welcome relief from monotonous expanses of concrete and asphalt. And it’s true that vegetated railway lines can help keep cities cool and manage storm water runoff (although how well lawn does this is debatable). But what about the energy consumed by mowing? Are fertilizing and irrigation required? I’d be all for it if native short-grass ecosystems were being seeded in along railways, but Inhabitat is lauding countless acres of manicured turf.

While I’ve been off for the past three weeks celebrating the holidays and doing site visits for a public garden project I’m working on, news of the following green city plans has been reported, courtesy of Inhabitat. 

For a neighborhood of Gothenburg, Sweden, currently covered with parking lots and football fields, comes this plan for a “garden block” nestled beneath a series of green roofs shaped like undulating hills. These green roofs insulate the buildings below while absorbing rainfall that can be purified for household use. The project also includes space for community cultivation of fruits and vegetables.

Meanwhile, outside of Milan is a planned development of high-rises with stacked planted terraces surrounding a large municipal park. The complex will be completely self-contained, with schools, sporting facilities, and a shopping center, saving energy by reducing the distance residents will need to travel in the course of their daily lives. Photovoltaic panels will help shade sunny windows while generating electricity, and solar water heaters will also slash energy use.

I admit it—I’m as seduced by the idea of verdant buildings as the next plant nut. On a purely aesthetic level, structures with living walls are a major improvement over the granite and glass monoliths that rise from the typical cityscape like enormous gravestones. But before we fall head over heels for green walls it’s worth asking whether they’re all they’re cracked up to be. Do they really, as touted, help insulate buildings, filter particulates from polluted city air, counteract the urban heat island effect, and create habitat for insects and spiders? Or are they just a green veneer, a 21st-century version of the fussy millwork that decorated Victorian buildings? Or worse, do they actually eat up more resources than they save? 

Even the green-minded bloggers at Treehugger and Inhabitat have been drooling over the latest designs, Daniel Libeskind’s 900-foot New York Tower, an upscale residential skyscraper with a section of glass curtain wall cut away to accommodate vegetated balconies, and Rotterdam-based MVRDV’s cluster of cone-like structures with concentric rings of boxwood-lined terraces intended for a new city south of Seoul. From a biological point of view, only one of the “11 Buildings Wrapped in Gorgeous Green and Living Walls” in this glowing review is interesting—Sharp & Diamond’s 50-square-meter green wall of wildflowers, ferns, and ground covers at the Vancouver Aquarium that seems to be based on plant associations found on cliffs, scree slopes, and other natural analogs. (If you haven’t seen it, take a look at The Urban Cliff Revolution, which suggests that these natural habitats have a lot in common with skyscrapers and other features of the modern city, and can serve as “habitat templates” for green walls and roofs.)

But what about the carbon footprint of the growing media used to create green walls, and any fertilizers used to sustain the plants? Is irrigation required? If so, is there an integrated graywater system in which used water from sinks, dishwashers, and other sources is cleansed by the plants and growing medium and piped back into the building to flush toilets? In short, do the environmental benefits of green walls outweigh the costs? I’d love to see some hard data.

This weekend in Berkeley, experts from a variety of disciplines including architecture, structural engineering, greenhouse growing, composting, alternative energy, aquaculture, hydroponics, integrated biological systems, sustainable farming, and urban agriculture are meeting for the first summit on vertical farming in urban areas, also rather inelegantly known as building-integrated sustainable agriculture.

The summit’s co-organizers are Keith Agoada and James Kalin, founder and technical director, respectively, of Sky Vegetables, launched by Agoada to build hydroponic greenhouses on the rooftops of grocery stores. A list of presenters and presentations will be posted on the Sky Vegetables website at the close of the conference. Their prototype system is featured on the site. 

If you’re headed to the Venice Biennale in the next couple of months, check out the latest figment of MAD Architects‘ imagination — Superstar, a mobile, self-sustaining city capable of housing, growing food, producing energy, and recycling the waste of 15,000 people. The Beijing-based firm conceived Superstar as an alternative to the “sloppy patchwork of poor construction and nostalgia” (if not the astonishing diversity of the vegetable markets and array of restaurants) of the typical Chinatown in cities around the world. The sparkling, three-dimensional star-shaped superstructure, which has been described as looking a little like a Cylon Base Star from Battlestar Galactica by Inhabitat, will be able to travel around the globe, providing a taste of Chinese cuisine and culture wherever it docks.