L from Lynchburg, Va writes
Per the product label, make applications of Monterey Garden Phos Systemic Fungicide before disease development and in conjunction with good cultural management practices. Use higher rate of application when disease pressure is severe. Do not apply to plants that are in a state of dormancy. There is a great article here that suggests it should be applied above 60 degrees and when rain is expected.
Answer last updated on: 12/26/2018
