Not all tree problems start above ground. Some of the most damaging threats are hiding beneath the soil — and Phytophthora is one of the biggest troublemakers. Although often called a fungus, Phytophthora is technically a water mold. It thrives in overly wet, poorly drained soils where tree roots struggle to breathe. Once established, it attacks the fine roots responsible for absorbing water and nutrients. Ironically, trees suffering from Phytophthora often look drought-stres