Sweet Gum Interior Yellowing in Ohio: Drought Response & Soil Check

Mid-summer interior leaf drop on a 4–5 yr sweet gum in NE Ohio is usually drought-induced, not disease.

Primary Cause: Summer Drought Abscission

• Trees shed inner/older leaves to conserve water when soil moisture drops.
• Occurs weeks before normal fall color.
• Fix: Deep soak (1" water) weekly during dry spells—soaker hose at drip line for 2–3 hrs.

Secondary: Soil Toxicity / Nutrient Imbalance

• High boron, pH extremes, or salt buildup cause odd leaf symptoms.
• $35 soil test (OSU Extension) identifies issues.
• Amend per results: sulfur for high pH, gypsum for sodium, leaching for boron.

What to Watch

• New growth at tips = tree is healthy.
• Progressive twig dieback, bark cracking, or fungal conks = call arborist.

Water first. Test if it continues. Most likely: just a thirsty tree in a hot July.