Crimson King & October Glory Maple Issues: Planting Stress and Phyllosticta Leaf Spot

Case

Long Island, NY: Crimson King + October Glory planted early June. Mild, wet summer. Crimson: dry curled leaves despite watering. October Glory: small black leaf spots, some damage. Fertilized with PHC Tree Saver.

Planting Timing Error

• Hardwoods best planted Fall or early Spring (pre-leaf).
• June planting = heat/moisture stress on new roots.
• Fertilizer burns new roots — stop fertilizing.

Crimson King: Watering Method

• Mulch 3" max, not on trunk.
• Deep water: 1" every 4th day (pan test: sprinkler until 1" in pan).
• Check planting depth: root flare at ground level.

October Glory: Phyllosticta Leaf Spot

• Fungus: Phyllosticta minima.
• Spots: circular, tan with purple-red borders; black fruiting rings in season.
• Affects: Amur, Japanese, red, silver maples.
• Damage: minimal (late season infection).
• Control: Fungicide (mancozeb/chlorothalonil) at spring leaf-out — but rarely needed.

Fertilizer Plan

Hold 1 year. Then 10-10-10 at 1 cup/inch DBH (small trees) or ½ label rate. Water in well.