Raywood Ash Leaf Drop in Heat: Overwatering in Clay Soil

A 24-gal Raywood ash planted in May in N. CA (105–113°F heat) dropped green leaves. Owner watered more, then less. Soil is red clay, moist at 18 inches. New tip growth looks okay.

Diagnosis

Too much water in heavy clay. Clay holds moisture; roots suffocate. Leaf drop is a stress response.

Corrected Watering

• Frequency: Every 3rd day if no rain; weekly if rain.
• Amount: 1 inch per watering (pan method).
• Check: Soil should be moist, not soggy, at root depth.

Why New Growth Is Fine

Terminal buds are more resilient; older leaves shed to reduce transpiration load. Adjust watering now—tree should stabilize.