For home gardeners, spring planting is just a few weeks away. But if you're planning to add fertilizer to the soil, reading the product's label won't always tell you whether it's safe. In most states, including Minnesota, manufacturers can sell fertilizer containing arsenic, lead, cadmium, and other heavy metals without disclosing those ingredients. In Minnesota, that means a product called Ironite is still on the market, despite high levels of contamination. Minnesota Public Radio's Mary Losure reports.