Chapter 4: Concluding Thoughts

I hope I have succeeded in imprinting in your mind a vision for what cities could become. I hope that, like me, you will no longer be able to drive through a city with flat roofs on homes or major buildings without thinking, “There could be a garden there...and there…and there! There could be acres/hectares of food-producing gardens in this city!”

This vision can happen and you can be part of it. The world needs "urban gardening champions" who will spread the vision, learn and adapt by experience, then build demonstration gardens to show people that they too can use the techniques you have refined for their situation.

I hope you will share your experiences with me and with ECHO. If you start working on rooftop or above-ground gardening and run into problems, drop me a line at echo@echonet.org. I or someone else at ECHO may have insights that can help you work around the problems. When you have successes, tell us about them. We can rejoice with you and can encourage others by sharing your experience.

I would also like to share excerpts from correspondence on this website. Be sure to include contact information when you write and indicate whether we can quote you. Photos are welcome. The few rooftop gardeners in this world are very widely separated. Sharing experiences of a network of rooftop and above-ground gardeners could be an encouragement to many.

With your help we can see enormous amounts of food produced and improved incomes for many ordinary people as we help them develop this last agricultural frontier-the one above us.

Hopefully you can adapt some of the techniques we have discussed to enrich your own life too.

Summary of Advantages and Special Applications of Aboveground Gardens

Aboveground gardens on platforms protect plants from animals and floods and are more responsive to limited ability to build up the soil fertility. There are substantial areas near the Amazon River in Brazil where most gardening is done in shallow beds on platforms. Local people have differing explanations for why this is done. During a visit to Santarem, a city about 500 miles from the mouth of the Amazon River, I asked a few people why they went to the effort to construct platforms for their vegetables. In flood-prone locations the advantage is obvious, but platform gardens in the region are a primary gardening method even where it never floods. Some say that they plant gardens on platforms to avoid damage by small animals. In part the platform gardens have most likely become tradition and some gardeners may do it just because that is the way it is done. Wayne Smith wrote ECHO, "They make a 4-7 foot-long platform of sticks, an old canoe etc. They place a layer of dirt and ashes/cinders on top, and then grow mainly green onions." I have also heard that some farmers of Mayan descent in southern Mexico use the same technique.

Soils in some regions of the Amazon basin contain a lot of aluminum. When soils are highly acidic, as is the case in this location along the Amazon, the aluminum ion dissolves and is then toxic to many vegetables. The improved growing medium that is concentrated on the platforms may give much better results in such situations.

I have seen shallow bed gardens on platforms used in some countries to reduce the chance that chickens will destroy the young plants. It can be especially helpful to locate a seedbed on a platform for producing seedlings for transplanting into the garden. Development workers in Kiffa, Mauritania, near Rancho Ebenezer in Nicaragua and near Hinch, Haiti have found a lot of interest in adapting tire gardens for similar purposes, placing tires on structures made from poles.

They are ideal for making gardens for the handicapped. Any of the garden types we have discussed can be constructed on top of some sort of platform, making gardening available to people with physical handicaps that prevent them from working in the soil. If platforms are placed at the right height, people in wheelchairs can garden easily. The platforms can be constructed of inexpensive materials because the gardens weigh so little.

You can avoid soil diseases and pests. Root-knot nematodes are such a problem in Florida that some susceptible plants cannot be grown unless the soil is first sterilized. However, some fungi that live on decaying organic material kill nematodes. If we have enough organic matter in the soil we can sometimes get around the nematode problem. If we have 100% organic matter, as in some shallow bed and hybrid garden designs, or no soil, as in the wick and shallow-pool gardens, we have no root-knot nematodes. After a few growing seasons, however, the decay process is essentially over. At this point the nematode-killing fungi may no longer be present and nematodes can again become a problem, unless the bed is renovated with fresh organic matter.

Examples of some plants that are highly susceptible to root knot nematodes include squashes, cucumbers, green beans, and peas. Some vegetables produce a useable harvest in spite of being heavily infected, as can be seen by looking at the roots. A scientist specializing in nematode problems told me that this means these vegetables are actually resistant, that is they were susceptible to being infected but were able to sufficiently overcome the damage that they could still produce a crop. Examples that come to mind include okra, tropical pumpkins, and winged beans. These plants may give a reasonable yield but may die prematurely and, when pulled from the ground, display roots heavily covered by the characteristic knots. Some vegetables in my experience seem to be relatively unaffected by root knot nematodes, though I cannot say that they cannot be harmed by them. These include corn, sorghum, onions, tomatoes developed to be nematode resistant, cabbage, kale, collard, garlic chives, and many herbs.

There may be other serious problems with the soil may lend themselves to aboveground gardening, even in rural areas. For example, the soil may be exceptionally acidic or alkaline, be too sandy or have too much heavy clay, or be filled with rocks. In some urban areas the ground may have high levels of heavy metals as a result of pollutants over the decades falling to the ground in rainfall or just settling out as the winds blew them over the garden.

You can garden near or in the shade of trees. Aboveground techniques can be used to make beds on a sheet of plastic under trees. Any material that has no cracks or holes through which roots can grow can be used to make a the bed that is unaffected by nearby tree roots. Benefits are that tree roots are not damaged by tillage; the plastic prevents them from interfering with the vegetables; and many plants benefit from light shade. Tire gardens are especially adaptable and can be placed anywhere that provides enough light, even directly on protruding tree roots or on a pile of rocks.

Limiting Factors in Above-Ground Gardening

It is not difficult to list possible problems with aboveground gardens.

The poor may live in homes with rooftops that cannot even bear the weight of a person.

Those (presumably more wealthy) with the most substantial rooftops may have the least incentive to garden on them.

Fertilizers may not be available, especially fertilizers that contain micronutrients.

People may not be prepared to give daily care to a garden.

It may be difficult to develop a uniform formula for making the gardens when only recycled materials are considered.

Water may be scarce or have to be purchased.

Compost is usually not available unless people make their own, and motivation to do this may be lacking.

Urban gardening projects in general have a reputation of little payoff among many in the development community.

There are situations where any of these problems may be critical. However, the world is a very, very large place. If a certain technique is only suited to one percent of urban areas we are talking about millions of potential gardens. A creative mind and innovative and can-do attitude is helpful to see successful above-ground projects develop. An idea that, if successful, promises to make acres of prime, presently unused, arable "land" suddenly available for producing food and some income, is deserving of extra effort. We can begin with those thousands of situations where the above problems are not limiting, while we consider how to include more people in growing their own food.

Special Considerations

It is imperative that your first community project succeeds. Do not involve many people in aboveground gardening until you are sure you know what will work and have done it yourself for at least one season. The success of the first community project is more important than saving money on every possible ingredient. I think particularly of fertilizers. A common question is, "Why not use compost or manure ‘tea' instead of fertilizer?" It is possible, but it is far from foolproof. (See previous discussion of this topic.) If a gardening system is based on manure as the primary fertilizer it is almost certain that some gardeners will fail not because the methods themselves have a problem but because of inadequate amounts of some or all of the essential nutrients in the compost or manure tea. It is quite possibly cheaper (and certainly less offensive to the neighborhood) to use fertilizer than to haul in manure from the countryside. But more importantly, if it fails you will probably not get a second chance with the people who tried your "far out" idea of above-ground gardening.

Consider the market before promising people that they can make money on their gardens. A Colombian organization developed a shallow bed/hydroponic system with many similarities to what we discuss in this chapter. The project used donated rubbish--rice bran from a mill and wooden crates from an automobile parts shop--and recycled polythene from commercial flower farms. In addition to what the 130 participating families used themselves, the cooperative sold over three tons of vegetables each month. A major supermarket chain bought produce from the community. Once a week produce was brought in, weighed, and paid for on the spot. From the sale of vegetables grown on the roof, the organization could pay the rent on their center. This enterprise was highly publicized in news articles both in Colombia and elsewhere, and apparently was very successful for many years. ECHO was never able to make contact with the project directors. We heard that the project ended once the funding stopped, due to difficulty in obtaining the hydroponic nutrients. A person who visited the site told me that the murder of a key leader dealt a major blow to the project. While it was operating, a key ingredient was that when each garden was planted, the market for its produce was guaranteed. This no doubt took a lot of leadership to provide the quality control and regular supply required by a supermarket contract. But even lacking such leadership, the vegetables can still be grown and eaten at home or sold in the informal marketing system.

Where Are These Above-Ground Methods Being Used Today?

ECHO and several people in our network have been involved in projects for a number of years. At various times since the late 1980s there have been isolated rooftop gardens planted. Path Lahr, mentioned earlier as developing some of the methods we have discussed, is pictured below with the garden on the roof of his rented house in the early 1990s. During the few days I was their house guest all of the vegetables came from the roof of the house. Also pictured is a garden on the home of one of them Haitian staff working with Pat. A small organization started by Pat Lahr called "Haiti Gardens" still works in and around Port-au-Prince, Haiti.

ECHO and the Center for Citizen Initiatives sponsored demonstration rooftop gardens in St. Petersburg, Russia in the 1990s, in collaboration with Russian colleague Sasha Gavrilov. The combination of a population that loves gardening, a shortage of food at the time, and an exceptionally high educational level made this seem like an ideal location. Nearly every citizen lives and works in buildings with huge flat cement rooftops made of cement and coated with tar of some sort. But on my last trip to Russia, around the year 2000, the vision appeared to have faltered.

The main problem is in getting official permission to use the roofs. People now own the apartments in which they live and must collectively be responsible for the building. Individual gardeners-to-be have difficulty getting permission to use the rooftop. What if they damage the water repellent layer? Would-be gardeners are afraid that when the day inevitably comes when there is a leak, they will be held responsible (whether or not they caused the damage). Building residents and probably the building engineer are reluctant to let someone garden on the roof because the residents themselves gain nothing and do take on some risk.

Institutions can more easily establish rooftop gardens than can individuals because the director of the institution that decides to establish the garden also controls the roof. He or she is the one who must repair it should it be damaged by the garden or gardeners.

There are a modest number of rooftop gardens in St. Petersburg. One garden on an apartment building has become a mini-farm, producing onions, herbs, and growing some container berry plants for resale. In 1995 a large garden was planted on the roof of the main prison in St. Petersburg.