Thursday, February 21, 2013

Envisioning a New Food Policy

The California Food Policy Council, a collaborative group of local food policy organizations, has approved a working vision of a governing document called 'A Vision for a Healthy, Vibrant, Equitable Food System'. The document consists of ten points, covering labor, health, environment and education among others, as the fundamental building blocks of a new food policy. 

"Food and agriculture has a profound effect on the health and well-being of our communities and our natural environment. The goal of California's food and agriculture system must be to achieve greater health, equity and prosperity for our diverse communities and natural ecosystems. "

Read the full document here. Great map of where the good food movement is headed!

Thursday, February 14, 2013

Edible Rooftop Review - Part I

[Eagle Street Rooftop Farm, Brooklyn, NY]
Rooftops are one of the major underutilized spaces in cities and for this reason have long been targeted for greening efforts, from plazas and ornamental roof gardens of the early 1970s to today's rooftop farms and edible gardens. In this post I've highlighted a few of the technologies related to rooftop farming, and some case study farms that represent a spectrum of ways to incorporate farms on roofs, from technology to programming. This is only a small sample of all the urban rooftop farms out there -  if you think I missed an important one, please shout it out in the comments! If you're planning or designing a roof garden (edible or otherwise) an excellent resource is Roof Gardens: History, Design and Construction by Theodore Osmundson. For very small projects (think garden shed) Small Green Roofs by Nigel Dunnett is a handy resource. 

[Typical green roof section]

Soil-based roof gardens are classified as either extensive or intensive. Extensive gardens have very shallow soil profiles (2" or less) and can only support small, shallow-rooting plants like succulents. Extensive roof gardens mitigate urban heat effects and slow and store stormwater runoffs, but cannot support larger vegetation. Intensive gardens have deeper soil profiles, sometimes to several feet depending on the structural capabilities of the building and the plant material desired. Intensive gardens can support edible plants, shrubs and even trees depending on how they are designed. Sometimes these two are differentiated as greenroofs (extensive) and roof gardens (extensive). Planted roof systems typically consist of a number of layers designed to protect the roof itself from water intrusion, and vary most in the design of the growing medium, which must be both lightweight and able to hold water effectively. Rapid water loss to evaporation is one of the major challenges to roof garden plants. Other options for roof-gardens include planter boxes, hydroponic systems, and greenhouses.


[Gary Comer Youth Center edible roof garden, Chicago, IL]
Eagle Street Rooftop Farm, in Brooklyn, NY converted their entire 6000 sf warehouse roof into farmland, by installing an extensive rooftop garden wall-to-wall.  Crops are grown in beds of soil 4-7" deep, and sold in an on-site market and to local restaurants. The farm also runs education programs and is open to the public daily. Brooklyn Grange is a successful 2-acre commercial farm using an extensive roof garden design, also in NY. Both these farms embody the most traditional aesthetic of 'farm', as if a little piece of Kansas had been blown onto a Brooklyn rooftop.