Dogwood Leaf Scorch in Sandy Soil: Environmental Stress, Not Fungus

Young dogwood in Central TX (pure sand, dappled pine shade) has brown crispy leaf edges and tiny red spots on all leaves. Crepe myrtle 50 yards away has similar browning. Watering: 24-hr trickle 2×/week. Fungus?

Not Fungus: Environmental / Soil Problem

The uniform marginal scorch on all leaves + similar symptoms on unrelated species = abiotic stress.

Likely Causes

• Extreme soil pH: Pure sand often very acidic or alkaline—nutrients unavailable
• Nutrient deficiency: K, Ca, Mg, Fe—invisible in sand without organic matter
• Water quality/quantity: 24-hr trickle may waterlog sand or leach nutrients
• Salt accumulation: From irrigation water in sandy soil

Action Plan

1. Soil test (county extension)—pH, nutrients, salinity
2. Amend per results—lime, sulfur, compost, fertilizer
3. Mulch heavily with composted organic matter (3–4″)
4. Adjust irrigation—deep, infrequent; check moisture at 12″

Why Not Fungus?

Fungal leaf spots are typically scattered, irregular, with distinct margins—not uniform edge burn on every leaf across species.