EAT UPdown and dirty.
Let’s talk soil. If you ask a farmer and a green roof expert how to mix the ideal batch of soil, they will give you completely different answers. Farmers are interested in high levels of organic matter, which help to retain soil moisture and provide nutrients for the plants. Green roof experts, by contrast, prefer soil that drains water efficiently and is low in organic matter (generally between 8% and 10%). This low organic matter helps green roof soil (or “media,” as it’s called in the industry) to remain lightweight, which is crucial for most buildings.
So is there a happy median? How do you build lightweight soil that contains enough nutrients for agricultural crops? The answer is not so simple, and in fact, there are quite a few differing opinions on the subject matter.
Tactic 1 | Some farms, such as Eagle Street Rooftop Farm in Brooklyn (rooftopfarms.org), build soil every year. Their soil is high in organic matter and therefore heavy, but luckily the old manufacturing building below can sustain the heavy load. This type of row farming mimics that on the ground plane, where weight is not as much of an issue.
Tactic 2 | Some rooftop farms and gardens utilize lightweight planting media in their raised beds or containers. This type of soil is engineered to contain more mineral content, and may contain elements such as expanded clay or expanded shale. This type of production relies on heavy nutrient inputs, usually in the form of fertilizer or compost tea.
Tactic 3 | The lightest soil is no soil at all. Certain rooftop hydroponic operations grow crops in nutrient solution, which can circumvent the soil discussion altogether. In the U.S., rooftop hydroponic farms are situated in greenhouses, where the environment can be precisely calibrated. The weight in these systems is a function of the greenhouse and the equipment inside.
it’s more than just tomatoes
Why on earth would anyone want to grow food on a roof? For lots of reasons. Urban rooftop agriculture can enable communities to positively affect their health, environment, and economy, while simultaneously promoting the occupation of underutilized space and strengthening the local food system. When applied at a neighborhood or city scale, rooftop agriculture has the potential to increase food security and decrease the urban heat island effect, particularly when coupled with other city planning and landscape architectural strategies. Benefits vary depending on the scale of production, but even very small applications can positively impact individuals and communities.
Benefits of urban rooftop agriculture
Health benefits of rooftop agriculture include those within the realms of social health and human health. The social health benefits consist of the provision of green space, the occupation of underutilized space, community building, and a strengthened local food system. Human benefits can include access to fresh, organic food, improved nutrition, the promotion of healthy eating habits, and the reconnection of people with their food.
The Environment can benefit through stormwater runoff mitigation, the utilization of vertical space, a reduction in fossil fuel use and air pollution (from decreased food transportation), and possibly even urban heat island effect reduction (when applied at a city-wide scale).
The Economy can benefit from by keeping money within the local economy. Urban rooftop agriculture can also create green jobs and attract consumers to the area, and building owners can additionally benefit by capitalizing upon underutilized space within their property. In Singapore, for example, building owners sometimes rent their rooftops to farmers and gardeners. Imagine if you could rent a community garden plot on the roof of your apartment building, just like you rent a parking space in the garage. One day this could become a building amenity that is expected by renters.
rooftop beekeeping
European honeybee
According to urban apiarist Trey Flemming, bees that live in cities are generally healthier than their rural counterparts. Bees are broad spectrum pollinators, which means that they leave the hive and look for varied types of nectar sources. In the countryside, many bees end up visiting agricultural crops such as corn and soybeans, which are commonly doused with chemical herbicides and pesticides. By contrast, urban bees feed on local flora found within street plantings, parks, roof gardens, and vegetable gardens. These small-scale polycultures are generally not treated with herbicides or pesticides, and so the visiting pollinators do not bring chemicals back to the hive.
Trey co-founded Urban Apiaries in 2009 in order to sell local honey throughout the greater Philadelphia area. The business now cares for 32 hives, located in seven apiaries throughout the city. Several of these apiaries are situated on rooftops, such as those at North Philadelphia’s SHARE Food Program and Chestnut Hill’s Weavers Way Co-op.
Trey Flemming from Urban Apiaries
Inspecting the frames
Tens of thousands of European honeybees (Apis mellifera) surrounded us on the roof of SHARE Food Program as they went about their business, and we ours. Trey tended the hives by first spraying pine needle smoke to calm his busy workers, and then he removed each hive’s lid to inspect its contents. During the inspection we observed bees working the hives and honey cells of various colors. Trey removed the most mature supers from each hive in order to extract the honey offsite in his honey house. Urban Apiaries sells its honey in shops, markets, and farm stands throughout the city, and each jar contains the apiary’s zip code on the label. Visit the company’s website at urbanapiaries.com.
dreaming big
As discussed in the previous post, the importance of selecting the right person to write the book’s foreword is paramount. The most appropriate candidates for “Eat Up” fall within the categories of food writer, community activist, designer, and practitioner. Ideally, a prominent person in one of these fields will accept the invitation to write the foreword, thereby promoting their own goals while contributing to the growing rooftop agriculture movement. Writing the foreword could help the following authors to promote their own initiatives by addressing:
– Food author: food systems, food access, food equity, organics, nutrition
– Community activist: community building, education, food justice, public health
– Designer: roof access, building codes, integrated design
– Practitioner: feasibility, cost, sales outlets
My dream team top pick shall remain unnamed, but I searched high and low for a personal connection to this literary superstar. The one connection that I found did not yield the results that I hoped for, an so the jury is out on whether to approach the author via email, mail a manuscript and written letter, or schedule an appointment and fly across the country to talk.
diversified marketing
Writing a book is the easy part. The challenge seems to come with publication and promotion.
The first draft of “Eat Up” was targeted toward academia, and the tone was dry and, well, academic. The current version of the book is geared toward a much broader audience, which includes policy makers, practitioners, city planners, designers, community activists, economists, and academics. The book is very readable and its new content targets these varied audiences, but how do you attract these readers in the first place? The answer lies in promotion, strategically selecting a publisher, and finding a key person to write the foreward.
Since the book bridges several disciplines, the promotional strategies, publishing house, and foreward author would ideally target different audiences. If the publishing house is well respected in the design community, for example, then a food author should be approached to write the foreward. In theory, this method of diversified marketing will lure in a wide variety of readers, and help spread the word and push sales.
160,000sf north philadelphia rooftop farm
Philadelphia is blessed with a burgeoning urban agricultural scene, which provides residents with access to fresh, locally produced, often organic food. While most of these farms and gardens are concentrated around the city’s central and western regions, North Philadelphia contains a remarkable dearth of fresh food outlets.
SHARE Food Program is a nationwide food distribution entity that founded a local distribution center and urban farm in the Hunting Park neighborhood of North Philadelphia. The facility occupies a 180,000sf manufacturing building, and utilizes the surrounding site for at-grade food production and parking. In an effort to increase both production levels and the availability of fresh food for the surrounding community, SHARE is working with the Philadelphia based Community Design Collaborative to develop a design for a rooftop farm.
The 160,000sf rooftop will accommodate several types of production, and will also contain green roof areas (for stormwater management) and a photovoltaic array (to generate energy for the building). At this point in the design process the rooftop farm will likely facilitate row farm, raised bed, and greenhouse production, as well as bee hives, which already occupy the roof. Additional programmatic elements may include demonstration areas, composting bins, rainwater harvesting, and even an outdoor classroom.
Stay tuned for design updates, photographs of rooftop honey collection, and SHARE’s journey towards securing project funding.
book teaser
Productive rooftop farms and gardens around the globe continue to prove that rooftop agriculture is possible. The question, though, is not of feasibility; it is of viability. Is rooftop agriculture viable in the United States given the current environmental, economic, and cultural climates? How can we shape our policies, architecture, and culture to foster the long-term success of rooftop agriculture, particularly at the neighborhood and city scales?
“Eat Up” will reveal how urban rooftop agriculture is feasible at varying scales, depending on what conditions are present. Reshaping our political, architectural, and cultural conditions in an informed way can make rooftop agriculture a reality for more individuals and communities. The book is intended not only to educate the reader as to what is possible, but also to provide a springboard for innovation. As hopefully the first book ever published to exclusively focus on rooftop agriculture, the goal of the book is to explore the subject matter’s potential, to understand our limitations, and to breed inspiration.
an introduction to the author
With a passion for productive infrastructure, Lauren Mandel works as a Project Manager and Rooftop Agriculture Specialist at the Philadelphia based green roof firm Roofmeadow (formerly Roofscapes). At Roofmeadow, Lauren designs green roofs, oversees green roof construction, and is integral to every rooftop agriculture inquiry and project that the firm encounters.
Lauren began exploring the viability of urban rooftop agriculture while in graduate school at the University of Pennsylvania, where she earned a Master of Landscape Architecture. With six years of professional landscape architectural and green roof design experience, Lauren is in the process of refining her thoughts on rooftop agriculture in book form. If published, “Eat Up” will be the first book ever written to exclusively focus on rooftop agriculture.
In her spare time, Lauren lectures on green roofs and rooftop agriculture, and is currently assisting with the design of a potential 160,000sf rooftop farm in North Philadelphia. She also loves backpacking and extreme dog walking.