What do we know about heavy metals in soil? What do we know about lead exposure through soil and garden plants? What do we know about cadmium and arsenic in soils? What can I do if I’m at risk for heavy metals in my garden soil?
Some plants absorb excess nitrates or oxalates from the soil and store them in plant tissues. Toxicity problems can occur in animals which feed on these plants.
Excessive summer irrigation of oak and madrone trees may promote fungal diseases such as the oak root fungus (aka armillaria root disease) and crown rot.