Some cannabis cultivars can be hyper-accumulators of heavy metals. Genetic factors within different strains and stress on the plant can exacerbate heavy metal uptake. Their roots posses proteins meant to readily uptake zinc, copper, and iron. Often, heavy metals with similar chemical properties are bonded to these proteins instead. Additionally, the roots also produce chemicals, like citrate, which can make certain heavy metals more soluble and easier for the plant to absorb. Once these heavy metals are absorbed through the roots, the cannabis plant is very efficient at moving metals into the leaves and flowers. The natural detoxification process of cannabis plants can also result in heavy metal accumulation in the buds.

As a cultivator, you must be aware of all the potential sources of heavy metals in your inputs. Contaminated soil and polluted water are obvious sources of heavy metals, but airborne particles are also something to consider. Perhaps the biggest factor for heavy metal accumulation in indoor and greenhouse grow setups is fertilizer. Some fertilizers contain heavy metal residues that can accumulate in cannabis plants. we recommend checking your fertilizers for heavy metal sources. bio365 growing media is made exclusively with organic nutrients, selected in part for their low heavy metal content.