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Boxwood Phytophthora Root Rot: Subdue Fungicide Timing

Control Strategy

Phytophthora root rot in boxwood requires Subdue (mefenoxam) granular fungicide applied when soil reaches 50–60°F in spring. This is when pathogen is most vulnerable.

Current Action

Apply now to slow spread, but spring application is curative. Improve drainage if possible.

Shrubs: Balsam Fir Needlecast: Safe to Replant Balsams After Removal; Fungal Leaf Spots on Basil in Colombia; Marigold Leaf Damage: Identifying the "Silvery Scales" Pest; Root Rot in Garden Beds: Diagnosing and Treating Soil-Borne Fungal Disease; Powdery Mildew on Zucchini: Lime Sulfur or Copper Soap; Controlling Botrytis Mold on Impatiens in South Florida; Soil Solarization: Eliminating Persistent Impatiens Diseases; Managing Fungal Disease in Creeping Phlox: Pruning and Organic Fungicides; Treating Photinia Leaf Spot: Early Fungicide Application Is Key; Red Thread in Long Island Lawn: Resistant Varieties & Fungicide Options

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