Drought Stress

The northeast has had much less rainfall, in both amount and frequency, during the growing season in recent years. The resulting drought we are currently experiencing has a damaging impact on trees and other vegetation. While some smaller plants, like grass, show signs and symptoms right away, trees usually take longer, often taking a couple years to show stress.

In larger plants, like trees or shrubs, the fragile hairs on feeder roots that are closest to the surface in the soil are largely responsible for water uptake. They are also among the first affected by dry soil conditions. When this happens and root hairs die, the plant’s ability to absorb water is diminished. Water is a major component of the cells that make up a plant’s composition. It also helps transport and dissolve minerals the plant needs to form enzymes that help it grow and stay healthy. A lack of water directly affects a tree’s immune system and disease-fighting ability.

One of the main ways water is transported through a plant is through evaporation from the plant leaves, also known as transpiration. The water then cycles through the plant, down to the roots and back up. Any long-term disruption in the pattern of absorption will stress the plant out, eventually causing browning and leaf wilt. Plants also take in carbon dioxide for photosynthesis through the leaves, so any disturbance can result in less bud and leaf development. It can also cause a tree to shed leaves in a stress response.

Newly transplanted plants, particularly trees and shrubs, are most directly affected by a drought. They have already lost a portion of their roots for water absorption in the digging and transplanting process.

Recovery can sometimes take years for trees. All aspects of the tree’s growth are affected by water loss so repairing them can take a long time. Focusing on tree health, including infrequent deep watering, disease and insect control, and regular feeding, can greatly help a tree’s chance of staying healthy through a drought.