New Knockout Rose Leaves Curling: Mildew or Fertilizer Burn?

Diagnosing Leaf Curl on a Young Knockout

Spring-planted Knockout: fine for a month, then slight leaf curl. Bush looks healthy, no leaf drop, no visible insects, still blooming.

Powdery mildew: Fungus draws sap from leaves, causing curl as they dry. Treatment: 1 tbsp baking soda in 2 quarts water, spray daily.
Fertilizer burn: If curl is only on leaf tips with browning, excess fertilizer. Fix: Stop fertilizing for the season.

Observe which pattern matches. Both are fixable; the plant will recover.

Roses: Diagnosing Holes in Knock Out Rose Leaves: Slugs vs. Caterpillars; Managing Black Spot on Knockout Roses in Humid Climates; Lacy Leaves on Knockout Roses: Sawfly (Rose Slug) Damage; Yellow Leaves on Double Knock Out Roses in Extreme Heat; Reviving Stressed Knockout Roses After Transplant and Drought; Curling Leaves on Knock Out Roses: Multiple Possible Causes; Treating Powdery Mildew on Knockout Roses Naturally; Knock Out Rose Decline: Investigating Sudden Browning in Kansas City; Knockout Roses Losing Leaves in Atlanta: Drought Recovery Plan; Identifying and Treating Black Spot on Roses

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