Drought Injury
Many conifers
37 host plants
Last updated
Drought stress in conifers like noble fir, western hemlock, and western red cedar typically begins at the canopy top and branch tips where water has the furthest distance to travel through the tree. Needles yellow and drop prematurely, and you'll notice the outer crown thins faster than inner tissues die. Even when the entire visible canopy appears dead, roots may still be alive, though trees in this condition rarely survive long term. Winter injury, root weevil damage, and gopher damage can mimic these same symptoms exactly.
The challenge here is untangling drought stress from opportunistic pathogens and insects that attack weakened trees, making it hard to know which problem is truly responsible for decline. Newly planted trees are most vulnerable, particularly Leyland cypress hedgerows in maritime regions where competition and intra-tree shading compound moisture stress over several years. Deep, infrequent watering, mulching, and soil amendment with organic matter build resilience; planting drought-tolerant species on thin or rocky soils prevents the problem entirely.
Quick Reference
Management
Cultural Controls
- Maintain soil moisture through supplemental irrigation for landscape and potted trees.
- Trees require infrequent, slow and deep watering to allow water to penetrate soils and be taken up by roots.
- Plant drought tolerant species on soils more likely to produce drought problems such as thin, porus, or rocky soil.
- Grass, weed, and brush control will help get rid of competing vegetation and conserve existing water.
- Plant in the late fall or early spring to help establish root systems before annual summer and fall drought periods.
- Do not fertilize during droughts, fertilization increases growth and therefore water requirements.