|We have a community garden in NYC. We created it in a lot where a building had been demolished in 1969, and so expect to have lead in the soil among other pollutants. I've heard that Mustard plants withdraw lead from soil. Does anyone know of any other plants or organic methods of withdrawing pollutants from soil?|
|First let me say that almost ANY plant will take up some lead. It has not been proven at this point just how much and which ones would be best (or worst-depending on your concern) for this purpose. Planting crops for the removal of chemicals or metals in the soil is called "bioremediation" and research is still happening in this area.
First of all, have a soil test done. Be sure to explain your concerns and also describe what you are planning to grow. The soil test results should help you make a plan of action. You can call the Cooperative Extension Service at 607/255-2237 to get information about soil testing. Your safest bet might be to build raised beds using topsoil brought in.
There are things you can do to improve the soiland make it safer for your use.
1) If the soil is kept at a pH of 6.5 or higher the lead will not be "useable" by the plants. Your soil test should list pH. If it is lower than 6.5, you can add lime to elevate it. Use the recommended rates given by the Extension Office that tests the soil.
2) Add lots of organic matter to the soil. This also makes it more difficult for the plants to "take up" the lead.
3) If the soil test comes back OK, but you are still concerned, treat vegetables in the following way prior to eating: a) peel root crops, b) remove outer leaves of leafy vegetables(lettuce) and rinse the remainder in a solution of 1% vinegar to 99% water. c) keep children from eating the soil. That's probably the greatest danger in lead contaminated soil.