By Molly Redfield
Asphalt-strewn streets and blank-faced skyscrapers dominate city landscapes. But in recent years, cities have also become places where anything from rooftop pumpkin patches to herb-crowded windowsills flourish. With the right ingredients—healthy soil, enough sunlight, plenty of water, seeds, and, of course, the space to throw it all together—it seems as if urbanites can now grow a garden anywhere.
City gardeners must take into consideration uniquely urban concerns when growing food (Photo Credit: the Thrive Post)
But cities are still unique growing environments. Tall buildings can shade out the sun and block or redirect wind. Heavy metals or other pollutants may contaminate the soil. And space in a densely populated city might be difficult to come by. These are some of the concerns, among others, that urban agriculturalists must keep in mind to grow healthy and productive gardens.
Today, Nourishing the Planet highlights five tips that are especially relevant to farmers, gardeners, and other agriculturalists growing gardens in cities around the world.
Soil:Because many cities have a past of rapid industrialization, or are currently industrializing, their soils can contain toxic heavy metal byproducts such as lead or cadmium. Plants uptake these heavy metals through their roots and then incorporate them into their vegetative tissue. When people consume fruits, vegetables, and other products grown in toxic soils they are, often unknowingly, exposed to these contaminants. Children are especially vulnerable to heavy metals and, according to the World Health Organization, a blood lead concentration in children exceeding 10 µg/dL (micrograms of lead per deciliter of blood) is associated with cognitive impairment.
Urban growers have several ways to avoid contaminated soil. One method consists of simply overlaying healthy soils, manure, and loam over contaminated city ground. Instead of completely replacing soils, though, another remedial effort includes mixing organic matter and limestone with city soils. By decreasing the acidity of soils and making lead bind more readily to non-living organic matter, this technique prevents heavy metal uptake in plants. In fact, treating and replacing a depth of only seven inches of city soils can effectively protect the root layer of most common garden plants from heavy metals like lead. Lastly, growing produce out of raised beds or containers with healthy soil is another way for farmers to be certain that their produce is safe.