Things are looking up for rooftop farming in Philly.

I know, I know. Long time no post. Great to see you all again. I hope all you rooftop farmers out there are doing well.

What has PROOF been up to since our last post? Don’t let PROOF’s lack of self-promotion fool you. Over the last several months PROOF has been working hard to lay the groundwork for the proliferation of rooftop agriculture in Philadelphia. We’ve been planning and scheming to embark on a focused pilot project in 2011, growing intensively on one residential rooftop, scientifically documenting everything along the way to learn all we can about building effective planters, picking the right potting mix, choosing the most productive seed varieties, and urging the best yield from our plants. We fully intend to have a great summer.

PROOF is really excited about the possibilities for 2011 and beyond. If you want to be part of the excitement drop Jay a line (jay at

In the meantime, I’ve been told the link to the Community Design Collaborative’s report referenced in our most recent post is hard to find. HERE IT IS. It’s a big report so it may take a while to load up.

Also, check out Phil Forsyth’s inspiring article about rooftop agriculture. At the moment it’s the top post on his blog: Enjoy.

Spring is springing

Hi rooftop farming fans!

Yet another few months have passed between posts. We’re now right smack dab in the middle of spring. PROOF is inching along, making progress bit by bit. By bit.

No, we’re not going to be planting rooftop farms in West Philadelphia this year as part of our proposed “2010 ten roof pilot program” (can we pretend that was a typo and we really meant 2011?) but we’re meeting, planning some test plantings (on the ground) to investigate various potting mixes and scheming about how to build next generation prototype planters.

In early May we met with the team from the Community Design Collaborative and they gave us their final report. It includes detailed sketches of proposed planter designs, great suggestions for how to build the interior of planter boxes and thorough cost estimates, all told in the form of dirty limericks. It’s a great piece of work You can see the non-limerick version here. (the photo on the front page is what I see from my roof each time I go up there to tend my “crops.” Imagine all the farms that could fill those unused rooftops!) At some point I’ll separate out the individual proposed planter designs to make them more easily viewable on the site. This is not that point.

The early summer is going to consist of planter-building and planting experimentation, as well as figuring out how we’re going to address two important issues:

1) getting Philadelphia’s zoning code to be more friendly to rooftop agriculture, and
2) encouraging L&I to redefine what constitutes legal roof access for flat roofs that have rooftop farms.

The second point is a big one. Right now Philadelphia’s building code doesn’t consider access through a roof hatch to be a legal way to get up onto the roof other than for occasional maintenance. In order to create legal access you have to have a dedicated staircase and, if coming up from the interior, a pilot/head house. That’s a huge investment of money and space, and something well beyond the means of most Philadelphia roof owners. We’re trying to figure out a way to get L&I to modify its definition of legal access for roofs that are exclusively used for agriculture. Doing so will open up hundreds of thousands of Philadelphia’s flat roofs to potential planting.

Though the CDC team and most of our efforts so far have focused on residential roofs, we’re also opening up the idea of farming on commercial roofs. When we build our prototype planters we’ll try to create ones that work both residentially and commercially.

If you have any ideas about any of the above or would just like to help PROOF by volunteering your time and/or beer, e-mail me any time at “”.

PROOF and the CDC

Hi rooftop farmers! (Wow, I haven’t posted for a long time. Happy new year…)

For the last few months PROOF has been working closely with a team from the Community Design Collaborative to develop planter designs for the 2010 growing season. The CDC is a volunteer-based community design center that provides pro bono preliminary design services to nonprofit organizations like PROOF. The CDC’s team is composed of architects, a roofing consultant, a structural engineer, a landscape designer and a cost estimator…awesome.

PROOF has also been working hard on our own planter designs, coming up with planting schemes for the upcoming year and thinking hard about materials and costs. Along with the CDC, we’ve met with Philadelphia city officials — nice people from the Office of Sustainability, the Planning Commission, the Parks Department and the Water Department — to figure out intricate code and zoning issues relating to rooftop farming.

Will PROOF be able to plant farms on 10 roofs in the 2010 growing season as projected…? We’re working on it. We’re trying to overcome code, zoning, structural and other barriers to make something good happen.

On Sunday, February 7, from 4-6pm at Studio 34 in West Philadelphia (tentative date and time), PROOF will meet with the CDC and rooftop farming stakeholders from the community to discuss the CDC’s findings and figure out next steps. Want to join us? E-mail me, Jay, at “”.

Some rooftop farming background

I just posted a brief FAQ about what being a PROOF “farm host” for 2010 will entail. Of course the most important question is, “Does farming on rooftops work?” The answer…we sure as heck hope so! In addition to the fact that Nelson Mandela farmed a rooftop pretty successfully when he was in prison, and that rooftop farming has become enough of “a thing” that it recently was featured in a rooftop farming article in the New York Times, a few recent rooftop farming projects have popped up to show us it can be done. For example (all these links will open in a new tab or window):

— Check out the world’s first Rooftop CSA (as far as we know), built and farmed by Erik in Milwaukee.

— There is a rocking rooftop farming project in Chicago.

— Community organizations have been successfully farming rooftops in Montreal for years.

— This edible green roof in Brooklyn is amazing. (PROOF will be growing in planters rather than in green roof material, but this farm is still really great.)

— Some companies like Sky Vegetables have been growing on rooftops on a large scale by installing greenhouses and other great systems.

— There are also a few small for-profit ventures like My Farm in Berkeley that build farms in people’s backyards, much like PROOF wants to do on Philly rooftops.

Also, you can find great rooftop farming and other urban agriculture information at’s rooftop gardening page,’s guide to setting up your own edible rooftop garden, and’s International Rooftop Gardening Projects page.

Let us know if you find any more inspiring links.

Want to host a rooftop farm in 2010?

Recently word about PROOF has slipped into a couple of eco-friendly e-mail newsletters and people from around Philadelphia are contacting us with questions about how to become farm hosts for our experimental 2010 season (March to November). Yes, we are still accepting volunteers! PROOF has a good number of roof volunteers, but we could always use more. Most of our roof volunteers are in West Philly but we’ve been fielding questions from all over the city and plan to find some way to work in some capacity with everyone.

For those of you interested in volunteering your roof, here are the basic things you need:

1) a flat roof. The whole thing doesn’t have to be flat, but a good stretch of it should be.
2) reasonably easy access to that roof (via a door, roof hatch, out a window or other means of access that doesn’t require exterior ladders…though maybe a ladder going up one story is okay.)
3) a willingness to let PROOF staff and/or volunteers into your house two times a week (up to three times a week during peak growing season), so we can farm the produce
4) a positive attitude and an eagerness to work with PROOF throughout this experiment.

We’re interested in talking with renters but we’ll definitely require the owner’s written permission.

As a PROOF farm host (as long as we get a decent amount of grant money to pay for all this stuff 🙂

— A free roof evaluation by Cory Suter of Bioneighbors, a sustainable roofing company. (normally worth $100)
— Free planters, potting mix and plants, as well as free installation of your farm by PROOF volunteers (planter, mix, plants and installation an estimated value about $1000 per roof).
— Free maintenance of your farm by PROOF staff (estimating two visits a week from March to November to plant, care for and harvest produce, maybe three in the peak weeks)
— Free produce from spring to mid-fall of 2010. PROOF will try to give you at least a decent boxful of fruit and vegetables per week, with a bit less in the spring and fall and a bit more in the summer. We say “try” because the rooftop farm is in its first year and it’s therefore all an experiment, but we’ll do the best we can. (average value of a CSA – community supported agriculture – farm share equal to about what PROOF hopes to provide, $600)

Still curious? Some quick answers to quick questions:

— Q: Is this a “green roof” system?
— A: Not really. PROOF will be installing planters on your roof but won’t be putting soil or waterproof membranes on your roof, as are typical in a “green roof” installation. Green roofs are awesome though and if you want one, by all means do it!

— Q: Will the planters hurt my roof?
— A: PROOF is designing planters that will span party walls (the brick walls of your house that connect with the house on the row next door) so planter weight rests on them, not directly on your roofing material. We’re working on solutions for detached houses or twins.

— Q: What if I don’t have a hose bib upstairs?
— A: PROOF should be able to either run a hose up from a hose bib you may have on your first floor or use an adapter to get water from an upstairs sink.

— Q: Who pays for the water?
— A: Farm hosts do. PROOF is designing its planters to be self-watering, which greatly reduce water needs. Planters will also capture rainwater, so in rainy weeks or for a couple days after a thunderstorm we probably won’t have to add water at all. We’re planning to work with rain barrel collection projects to also enable the planters to be able to use as much rainwater as possible.

— Q: Won’t the soil dry out?
— A: PROOF is using self-watering planters (more on those in another post) that have covers — the plants grow up through the covers. Being covered, the planters don’t dry out and also don’t allow for much evaporation. Hence, the soil stays moist.

— Q: What can be grown on a roof?
— A: Almost anything that grow in the ground. There are exceptions, of course, though on the other hand some things grow particularly well in containers. As for what you can grow on your particular roof, PROOF will work with roof hosts to tailor a planting scheme to the fruit and vegetables you like to eat.

— Q: Do I have to keep the farm permanently?
— A: Nope. PROOF would love you to keep the planters after 2010 so we don’t have to dismantle them haul them down, but we don’t require that kind of commitment.

— Q: How much work do I have to do on the farm?
— A: None, if you like. Your main responsibility is to let PROOF volunteers into your house at the agreed-upon times. Of course you can absolutely participate in the farming to the extent you want. (We may also ask you to spritz the plants with water on hot days, or let a PROOF staffer in to do it for you.)

— Q: How much produce will I get?
— A: PROOF will try to provide your house with the equivalent of 1/2 to 1 full CSA share of produce from your roof. We will distribute excess by selling it at farmstands or in some other way. This will be one way PROOF will support its future operations. (PROOF is a non-profit but still needs money for infrastructure).

— Q: Will the produce be organic?
— A: PROOF won’t have organic certification in 2010, but everything used from potting mix to fertilizer will be organic.

— Q: What if I don’t have access to my great flat roof?
— A: PROOF is working with green roofers who install roof hatches. We’re hoping to be able to help financially if you want to do that.

— Q: How much will this all cost me?
— A: If PROOF gets grants and donations this fall to support the project, zero. If we don’t….we’ll talk.

Please let us know if you have any other questions and we’ll try to make up answers.

It’s like a forest up there

Here are a couple photos of the pretty encouraging plant growth on our roof at 44th and Pine, starring almost-five year old Molly and just-two year old Lily.

These plants are growing in plastic tubs that were pseudo-earthbox experiments from last year:

rooftop farming at 44th and Pine, plants in 2008 experimental planters

rooftop farming at 44th and Pine, plants in 2008 experimental planters

Up on the roof at 44th and Pine on July 1, 2009

Up on the roof at 44th and Pine on July 1, 2009

Here are tomato plants abounding in this year’s experimental planter. No root rot yet.

plants booming in 2009 experimental planters on July 1, 2009

plants booming in 2009 experimental planters on July 1, 2009

Exciting rooftop farming updates!

There are a lot of them.  Here are a few:

1. the 10 Roof Pilot project for 2010:

Response has been really great to our call for “farm hosts” for our 2010 pilot project. We have more than 10 potential hosts, with more enthusiastic e-mails coming in each day.  Over the next couple weeks I hope to check out the volunteers’ roofs and see if we do in fact have all 10 slots filled. Thanks to Gina, Tammi and Josh, Josh and Hannah, Alisha and others who have recently stepped forward, and to PROOF’s own prototype planter co-designer, Andrew, who should have a roof of his own to offer by the end of the summer.

2. Money

People have been offering money…!  Sort of.  At least, I’ve been talking with a variety of individuals and organizations about their desire to financially support the rooftop farm project.   If you are part of, or know of, a foundation or any other entity that might get behind the idea of transforming Philadelphia’s 400,000 flat roofs into viable organic farmland, drop me a line.  (

3. The University of the Arts Sky Farm

I met on Tuesday with Tony Guido and his class of industrial designers at the University of the Arts.  They’re planning to build a farm on the 4,000 square foot concrete-reinforced roof of their main building at Broad and Pine (the Gershman Y building).   We talked about working together on planter prototypes throughout the fall and winter. Ryan and Cory have also met with them over the last few weeks, so they’re definitely in on what PROOF is up to.

4. Community Design  Collaborative

This week I talked with the project manager of the Community Design Collaborative, an organization that helps non-profits with design and other kind of planning for projects just like ours.   She suggested PROOF apply to be part of their next round of supported projects.  The application deadline is July 15.  If they agree to work with us we’ll have their professional designers, architects and engineers collaborate with us over the winter to design amazing planter systems.

There’s other news, but I’d rather leave you wanting for more.  In the meantime, check out this article from about urban farming:

Have a great day