Drought Recovery Program for Trees

Irrigation: Water stress inhibits the manufacture of key plant growth regulators that control dormancy. This may increase the chance of winter injury. Irrigate dry soil beneath trees to a depth of 12 inches during the fall months. Without rainfall, plants require the addition of approximately 750 gallons of water per 1000 square feet of soil surface beneath the crown during each week of the growing season.

Mulching: Mulching trees with organic materials, such as wood or bark chips, provides many plant health benefits. Mulch conserves soil moisture, insulates soil to reduce winter injury and improves the physical condition of soil. Apply mulch to a depth of 2-4 inches around plantings. Avoid contact with stem.

Soils and Nutrient Management: Plants should be fertilized in fall or spring following the drought when soils are recharged by rainfall. Avoid fertilization during droughts because it provides little benefit when water is the limiting growth factor. Additions of commercially available mycorrhizal fungi to soil will benefit drought stricken plants, especially mature trees. Mycorrhizae inoculants stimulate root development and improve the absorption efficiency of those roots.

Pruning: Clean to remove dead, damaged and dying branches and to reduce pest problems. This reduces the demands for water and nutrients. Thinning must be done judiciously because excessive pruning can weaken the plant.

Integrated Pest Management (IPM): Moisture stressed plants are more susceptible to insect borers, bark beetles and root, stem and foliage diseases. Cool season mites are a particular concern on hemlock. Trained technicians periodically inspect plants and apply treatment for pests and health.