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Knock Out Rose Leaves: White Spots → Holes = Shot Hole Fungus

Whitish spots turning translucent then holing = shot hole fungus (a mildew). Caused by warm days/cool nights. Treat with any rose fungicide or 1 tbsp baking soda / 2 qt water sprayed daily until cleared. Ensure good airflow; avoid overhead watering.

Roses: Reviving Struggling Knock Out Roses After Transplant; Restoring Bloom Size on Double Knock Out Roses: Pruning Frequency and Fertilization Schedule; Deadheading Knockout Roses: Snap, Don't Snip—And It's Optional; Overhead Watering for Knock Out Roses: Why It's Acceptable and How to Do It Right; Planting Double Knock Out Roses in Atlanta: Frost Tolerance and Establishment; New Knockout Rose Leaves Curling: Mildew or Fertilizer Burn?; Reviving Stressed Knockout Roses After Transplant and Drought; Treating Powdery Mildew on Knockout Roses with Baking Soda; New Knockout Roses: Purple Leaves and No Blooms – Transplant Sulk; Rose Rosette Disease: Why Knock Out Roses Aren't the Only Victims

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