Over the weekend, a friend mentioned that her yard, in South Portland, Maine, wasn’t suitable for growing edible things. “It has high lead content,” she said.
Call me naive, but I had no idea that vegetables would absorb heavy metals in the soil and pass them on to the consumer, but her concern got me thinking about potential issues with urban gardening.
Urban gardening has taken root across Los Angeles, most notably in South L.A., where “guerrilla” gardeners are taking over curbside plots and attempting to create oases in that particular food desert. This movement is cause for celebration (and castigation of the city, which is attempting to crack down on urban gardening for spurious reasons.)
South L.A. needs gardens and gardeners, but it also might need soil testing. According to the city, Council District 9, which comprises much of South L.A., had the highest number of reported lead poisoning cases in the city between 2004 and 2009. (Council District 1, downtown, had the second highest). These areas are also the ones that most need gardens.
I did a little research, and it turns out that my friend was half right about the dangers of gardening in lead-contaminated soils.
According to the University of Rhode Island Landscape Horticulture Program, “Vegetables and fruits can accumulate lead in their leafy green tissues, although lead accumulation will be lower in fruits. In high-risk lead areas, grow crops such as tomatoes, eggplants, peppers, squash, melons and cucumbers rather than leafy greens such as lettuce, chard, collards or spinach.
“Crops such as carrots, radishes, turnips, onions and potatoes can accumulate lead and should not be planted in heavily contaminated soils.”
In other words, my friend is probably OK growing her own tomatoes and eggplant — but do-good urban gardeners might need to think twice before passing out heads of lettuce to the local kids.
Even if soil is tested, urban gardeners should beware. More lead is deposited on plants by urban dust than is absorbed through the roots, according to the National Gardening Association in its helpful guidelines on gardening in the presence of lead.
It does sometimes seem like no good deed goes unpunished, but in this case, a little knowledge might go a long way.
