Q.Lead Levels in the Soil
I would like to make a raised bed for growing vegetables but know that the existing soil is contiminated with lead. Is there some kind of soil barrier I can put down and cover with healthy soil and grow veggies risk free?
Certified GKH Gardening Expert
Peat is thought to possess an excellent metal binding capacity. In addition to peat, gypsum and lime may be suitable as fixing agents in lead-contaminated soils. Cover this with layers of moist newspaper and then add soil. The most effective way to reduce the level of lead is to add compost and mulch as much as possible. There are also specific types of crops (like leafy greens) that you can plant and then dispose of prior to planting anything else. These plants naturally absorb large quantities of harmful chemicals, making them ideal to use them in order to soak up the unwanted toxins. However, remember not to ingest these plants—you must dispose of them and avoid throwing them into the compost pile. Also, keep in mind that lead only leaches downwards, so as long as your raised bed is 6-8 inches deep, most of your plants should be safe.