Jacob writes:

Hi agrists,

I saw this at my local grocery store in Minnesota over the weekend and the first thing I thought of was how nearly all of these vegetables could be grown locally during the winter with an indoor farm.

Best regards,



Jim writes:

Hi guys,

I’m getting old too, Dickson, and am concerned about our planet, so I greatly support your effort and those of your allies.  And, since work in your area is so diverse that what you’re doing is about as close to a discussion group as we can get, I’ve turned to letting others know what you’re doing by sending information about your podcast to some 15 other podcasters who may have an interest, such as OnPoint, the Diane Rehm Show, Agroinnovations, Big Picture Science, RadioCurious, LabOutLoud, TechChicks, Naked Scientist, CBC Ideas and Freakonomics, as well as the Boy Scouts and 4-H organizations. So you will, hopefully, be contacted by a few of them and that may work better than any discussion group approach.

I also want more information about the smallest scale versions of this and had been frustrated, generally, by even small systems costing many multiples of any resulting product, disregarding the labor. Fortunately, there is some information about some very interesting approaches available, to families, kids, schools and other organizations. I found two great concepts, one using buckets and the other using a section of gutter and water control valve for a toilet. Here are the links: Build a Self-Watering Container, and gutter that may be of interest to your listeners.

You also mentioned a desire to keep the growing process labor-intensive so more people are employed.  I agree, but see that the site with more basic approaches, also has the following discussion about the use of arduino microcontrollers.  I hope we end up with a useful blend of high and low tech. This latter approach may be more interesting to some of your listeners.

The source of the non-commercial approaches, Root Simple, is run by some folks on the West Coast who have been at it for a few years. They might be interested in doing a podcast about their grassroots approach to urban agriculture.

Please keep up the good work and thanks.


Smithfield, VA

June writes:

Hi Dickson Despommier and Vincent Racaniello,

Great podcast!

You might be interested in this Urban Ag segment on the podcast and CBC radio show Spark:


Best regards,


Jim writes:

John Morris lives in my area and a couple years back he started an aquaponics business. I just wrote him about the Urban Ag podcast and suggested he do an episode with you. Here’s a link that provides his background: John Morris grows herbs and vegetables aquaponically at his Herb Aqua Farm in Smithfield.

Regards,  Jim Vandiver, Smithfield, VA

Simon writes:

Hi Vincent and Dickson,

In response to Bills letter regarding using Nitrogenous waste as a resource for vegetable production.

Blue Smart Farms are an Australian company who have developed a nutrient management system that takes fish waste and converts it to plant available nutrients by processing through a bioreactor and a vermiculture system.

We are able to efficiently manage the nutrients to enable production of high volume commercial scale organically certifiable vegetables (eg herbs, salads) in a protected environment.

The nutrient management technology is equally suitable for a vertical as a conventional horizontal growing system.

Our licensee in Sydney is currently producing 129,000 plants every 28 days, and around 20 tonnes of Australian Sea Bass a year, from one acre of growing space.

Please contact us if you have any questions.



Director, Bluesmart Farms

Jochen writes:

Dickson, Vincent,

I’ve just listened to UrbAG 14 (as I am a fan of the concepts and the format) hearing about your wish for a vertical farming video game among other things. I would like to share with you that there is such a game already. „Arte“ a French/German public TV Channel which featured vertical farming in a series of programs on the future of cities which was just aired in late January and which also featured you, Dickson, has put up a video game called “Speedfarming 2050, the game” on their website. It is not a highly refined game-production (although I am not a gamer), but it puts running a vertical farm at the center of a play and thus allows you to get more familiar with aquaponicly raised food from an indoor vertical farm.

I consider the episode of the TV-program dealing with VF a very effective way to get a head start on the subject if you speak German. I suspect it is also available in French. You can find the game and the video at http://future.arte.tv/de/staedte-der-zukunft

Allow me to congratulate the both of you on your podcasts and on enlightening us on the concepts which I feel very passionate about.

Keep up the good work and keep up bringing on such interesting guests.


Bad Homburg, Germany

Peter writes:

Greetings urban agriculturists.

I was searching for examples of urban agriculture in the UK and found some examples that may be worth mentioning on your podcast.

Growing Underground is an urban farm located in an old WW2 deep bomb shelter under South West London which had been unused since 1945. It is the work of entrepreneurs Steven Dring and Richard Ballard together with Michelin-starred chef Michel Roux Jr.


Another UK company is GrowUp Urban Farms who sell fresh fish, salads and herbs.


The talk of seaweed farming in the last episode of Urban agriculture brought to mind Dr. Kathleen Drew, the British scientist who determined the life cycle of the edible seaweed ‘laver’  Porphyra umbilicalis, which has alternating haploid  and diploid generations, these were previously thought to be different species.

When her work was read by a Japaners biologist he realised that this had to be the life cycle for nori, a related edible seaweed used to wrap sushi. The nori industry had been devastated in the late 1940s by typhoons that disrupted the shallow coastal regions where the nori grew. Almost nothing had been known about the nori life cycle, so no one knew how to establish new algae to repopulate the depleted seaweed beds.

With the new information on the nori life cycle, Japanese scientists were able to quickly establish a nori farming as a reliable industry.

As a result Kathleen Drew is famous in Japan, a monument to her was erected in 1963 at the Sumiyoshi shrine in UTO City and a celebration is held there every year on 14th April.

Here is a link to a BBC programme about the festival:


Sascha writes:


First off, Your podcast is absolutely fantastic. Thank you for this invaluable educational resource.

Now onto the meat of the message:

My name is Sascha Kyssa and I’m very interested in commercial hydroponics. My undergraduate degree involved studying biology, ecology, organic agriculture, closed loop agriculture, and hands-on urban farming. I’ve developed a number of community supported agricultural gardens in Iowa, worked on large-scale agroforest systems in Hawaii, and dabbled in compost systems in Haiti. Now I’ve taken the plunge (no pun intended) into hydroponic systems. I’ve looked into Illumitex lights, and the numerous techniques for growing hydroponically. Despite a strong background in agriculture, I’m still a bit lost as to what is the most efficient commercial hydroponic system. Do you have a condensed resource list for new hydroponic farmers? Or perhaps an Urban Agriculture Podcast seal of approval for specific books, DVDs, and courses?

Most importantly I have a few questions for Dickson 🙂

My questions include: Are all Illumitex lights 68% efficient? Is there an industry standard for commercial hydroponic training? Is there a specific online or in person course you would recommend? And most importantly, is there peer-reviewed research comparing the nutrient levels of hydroponically grown plants to organic (ideally soil-food-web) soil grown plants?

Thank you for all that you do!

Mr. Kyssa

Robin writes:

Dear Dr.s Vincent & Dickson

The Urban Agriculture and Vertical Farm concepts are disruptive and paradigm shifting. They appear poised to displace a lot of other systems.

However, along some other systems, Wile E. Coyote, Esq., Genius is at the moment feeling around with his toes for solid ground, having run off the cliff, before looking down.

Dahr Jamail: “Are We Off the Climate Precipice?” 


Food on the Starship Enterprise comes from the synthesiser, of course.

How tight is the link between oil, food and population?


Urban Agriculture and Vertical Farming will be viable when they are 100% fossil fuel free.

Rose writes:

Hi Guys, I am just a housewife/grazier in Australia. I have always been involved in a home veggie garden and orchard. I have always loved the experience of producing and I am now passing the enjoyment onto my girls. Before I heard your podcasts I thought hydroponics was a waste of water. Little did I know. Thank you for putting things straight for me. I wish I had the knowledge and money to start an indoor farm in outback Queensland, to beat the heat, insects, drought, frosts, hot wind, hail, heavy rain, etc., etc. Wouldn’t it be amazing for people to be able to eat fresh produce in areas it can’t be grown without having to transport it hundreds of kilometres after picking it green or breeding the tomatoes to be like rocks. Anyway, keep up the good work. I really enjoy your shows. Rose.

James writes:

Dickson and Vincent:

Enjoy your Podcast, keep up the good work!

My name is Dr. James M Ebeling and in partnership with Dr. Michael Timmons at Cornell University, we teach a short course several times a year and have written the engineering text book on Intensive Recirculating Aquaculture Systems.  Over the years we have seen in increasing interest in aquaponics and now include a whole day on hydroponics and half-a-day on aquaponics.  We have several commercial facilities constructed by former students and one in New York Continental Organics, http://www.conorgnx.com/, is a large commercial operation using aquaculture to provide nutrients to its lettuce and basil operation.

I would be excited to participate in your program to bring a sound engineering basis to the other half of the aquaponics systems, i.e. recirculating aquaculture.  If it helps to increase my background, I work with Gene Giacomelli, here in Tucson and lecture on aquaponics at the CEAC Greenhouse short course, next week.  Currently I am retired after thirty years as an aquaculture engineer, and moved to Tucson to do NOTHING.  Alias,  I find myself involved with Gene at the CEAC, the local aquaponics group, several high schools as well as consulting on aquaculture domestic and overseas.

The attached Power Point is the presentation I do at the CEAC short course and I’ve also include a link to my Public Dropbox that has lots of additional information.

So we have heard a lot from the biologists, philosophers, economist’s, liberal arts graduates, dreamers and tree-huggers, perhaps its time to talk about the real engineering problems and solutions to urban aquaculture.


James M. Ebeling PhD

Research Engineer

Russell writes:

Thank you both for your work on this new technology that could help the entire world to eventually achieve quality nutrition with a minimal impact on our planet!

This would be quite a wonderful thing to happen some day.

After reading the new idea of vertical farming, I thought perhaps this could be done on a small scale for a home. While my wife and I are the only ones living in our home, I would like to grow more food than we need to barter with neighbors, which will help build a better sense of local community in our area  and help us in our approaching retirement.

I have an area about 20′ long by 12′ high that could be built as a vertical farm facing south.  In the metric system that would be roughly about 3.7 meters high and 6.2 meters long.

My location is in Portland, Oregon, where we get a lot of cloudy and cool weather for half the year. Intermittent mild frosts last for about 75 days in the coldest time of the winter.

I would rather use sun light for the plants, enhanced by winter lights when the cloudy weather comes.

Also, perhaps fish can be grown using their tank water to water the plants as a natural fertilizer. The fish can be fed by spirea algae that feeds small fresh water shrimp. The spirea can be grown on weed/water tea that is added to the spirea tank, which drains into the fresh water tank, and then that drains into the fish tank. The fish will also feed upon insects that fly into a bug light above their tank at night. Purified fresh water would be added to the fish tank as needed if the nitrogen content gets too high.

Solar power would be preferred for pumping to keep energy costs down with conventional battery power to take over the nights and cloudy days.

This would be the first closed loop system using no artificial or external fertilizers of fossil fuel electric power except for weeds and insects that come from the rest of the yard.

How many people could this feed?

Small scale and affordable (under $20,000 USD), perhaps even having enough food to sell at the local farmer’s market would be a plus.

Is this possible?

Thanks for your work!

Claire writes:

Hi Drs. D and R,

Thanks for keeping up with the urbanAg shows! Here’s a couple of comments:

I was happy to hear Mr. Gordon-Smith talk about how farms might be scaled to actually fulfill dietary needs. Microgreens are great for upscale restaurants, but they aren’t very filling.

Would calorie dense foods like peanuts, beans and potatoes would work inside? If I recall correctly, they grew peanuts in Biosphere II.

I do acknowledge, however, that fresh greens are hard to come by, especially for people relying on food banks. See this article on Seattle’s Millionair Club growing hydroponic greens for foodbanks!

Also, I’d love to hear from some women and people of color involved in urban agriculture on the show.

Thanks, keep up the good work!

Claire (in Seattle)

Steen writes:

Dear urban agronomists,

I hope you guys do a show about an in planta vaccine production facility such as the one Dickson alluded to on UrbanAg 15—it sounds like the perfect intersection of the subjects of all your podcasts. Transient transformation based on Agrobacterium or virus vectors is fascinating.

Perhaps you will discuss transgenic crops and maybe even ‘DIY Bio’ at some point. As a biologist who uses transgenesis as a tool, I have always found the term ‘genetic modification’ imprecise. As noted in your early episodes, traditional genetic selection has altered plant morphology in far more dramatic ways. Arguments against transgenic crops often cite the precautionary principle, similar to arguments against doing experiments on potential pandemic pathogens. A new paper on sweet potatoes underscores the point that transgenesis occurs in nature and perhaps even contributed to domestication/improvement of a crop.

The Daily Show recently covered a transgenic potato approved by the USDA that is hoped to benefit consumers (less acrylamide is produced when it is fried), rather than just food producers. A similar TAL-Effector-Nuclease-edited potato was recently reported. The USDA has indicated that the latter potato will not require the long approval process required for new transgenic crop varieties.

Maybe these subtle terminological issues are a tough subject for a podcast. Some people get upset when the phrase ‘genetic modification’ is interpreted literally. Quite a challenge for science communicators.



p.s. I was amused by the suggestion (UrbanAg 1) that “a triple hybrid gave rise to the corn plant.” Out-of-date scientific theories can last for a long time! There was a spirited 30 year debate on the origin of maize. John Doebley wrote an good summary.

Jim writes:

Good Day to Ye Sir,

I’m recently writing on a newspaper web-site in response to an Editorial they wrote on the Fate of the near bankrupt Steamtown Mall in Scranton, Pennsylvania.

I ran across your web-site whilst doing some research on Urban Farming and find Vertical Farming intriguing in that context. I also provided a link thereto to hereto in my writings there.

I also ran across a web-site on LED lighting that is also fascinating and I provide that link forthwith: ‘Shoots in the dark: Farming without sunlight’http://www.independent.co.uk/news/science/shoots-in-the-dark-farming-without-sunlight-2360833.html

Following is a link to the Editorial run by the Scranton Times-Tribune I spoke of. If you find yourself bored with counting Buffalo; you may wish to be bored further by reading my comments there (below the Editorial) on suggestions for Urban farming. Be forewarned: I’m verbose as this comment verifies and you may wish you counted Buffalo instead.

‘Make mall auction first step back’ By the Editorial Board

Published: April 26, 201


Perhaps you would be kind enough to let me pick your brain a wee bit and add your own comments if you so choose.

PS: My SN seanachie translates to ‘Story Teller’ from Irish to English though I’m a true blooded American. Thank Ye kindly for your attention! Jim

Steen writes:

Candidate listener pick, related to your early episodes: Beadle’s fun retirement project—changes in just five genes were pretty much sufficient to transform teosinte into maize.


Shirish writes:


I am motivated and impressed with urban farming since the last few months.

Your podcast gave a very good insight and helped in firming the decision.

I would like to know the following.

  1. If you could help in partnering with a company for the Indian market who are engaged in providing solutions
  1. How can I know where the next seminar or exhibition is happening on urban farming




Steve writes:

Dear Dr. Despommier and Dr. Racaniello,

Thank you for your ongoing work in the Urban Agriculture. I have listened to a number of the dialogues, all of which have been extremely insightful, including the latest one on AeroFarms. Based on a bit of research into the field, I am looking into what options I might have to do a career transition into the business side of vertical farming. I have a few questions that I was curious whether you might be able to provide some direction. I am trying to map out the gaps, implications, and enhancement requirements, to determine where are the optional career position/opportunities.

– Has anyone mapped out the vertical farm sector from a business competitive analysis perspective? Are there a few folks who are looking at vertical farming from a cross-sector/comparative business perspective?

– Do you have an evolving list of all existing commercial vertical farms, their business model, and financial viability? My list of 20+ companies continues to grow, but delving into each firm’s business model is typically proprietary, so your interviews add some valuable light.

– Is there a complementary list of businesses in ag data analytics? Ag robotics? Ag-focused LED lighting? What other complementary sectors/opportunities exist for vertical farming.

– Do you have a list of future/potential interviews to be posted to your Urban Agriculture series?

Again, many thanks for your investment into the Urban Agriculture efforts,