Deep root fertilizing or feeding injects water, fertilizer and systemic insecticide directly into a tree or shrub's root zone, where most nutrients are absorbed. Here in El Paso, the soil is typically compacted, this process breaks up the soil, creating an easier path for air, water and nutrients to get to the root zone. While the fertilizer feeds the tree or shrub, the systemic insecticide protects it from pests, like brown spot, scale, and aphids. Winter is the best time for this treatment as plants and trees store nutrients for the spring during the winter season. This treatment can be done all year and is also effective for treating ailing or pest infested plants and trees.