Cabbages Aren't Just for Eating

The cabbage family is well-known for its variety of nutritious vegetables. Examples include: Brassica oleracea plants such as kale, Indian mustard, collards, broccoli, cabbage, Brussels sprouts, cauliflower, B. ‘Romanesco’.

It turns out that the same Brassicas (kale, Indian mustard, collards, broccoli, cabbage, Brussels sprouts, cauliflower, B. ‘Romanesco’) also absorb lead from the soil, called hyperaccumulation. The EPA says 18% of all our homes have soil lead levels above the recommended limit from the remains of lead paint, old leaded gasoline pollution, and nearby factories. The cost of mechanical, chemical restoration is much more expensive, six to ten times more expensive than using plants to remove lead.

Cleaning one acre of urban soil to a depth of twenty inches using plants costs between a projected $60,000 to $100,000, compared to $600,000 using conventional methods. More significant, planting and harvesting crops of Indian Mustard over three growing seasons would result in 500 tons of plant biomass to be disposed of by incineration. This figure is only 0.25% of the total 20,000 tons of soil that would require excavation and hauling to the nearest hazardous landfill through conventional removal.

Once you eat any of the above plants where lead exists, you’re eating poison. In urban areas you may want to have your soil tested for lead (about $50). Don't eat the vegetables and don't compost them, but do send them off to be disposed of by special incineration facilities.

BIO: Robert Kourik's books, blogs, and articles bring science to gardening. He has designed gardens for three decades and is a pioneer of edible landscaping, the art of growing food plants among ornamental plants.  He works throughout California and the country. Visit Robert's blog Garden Roots or go here to buy his books.