Rose Preventative Treatments

Black Spot of Rose – This page contains extracts from IFAS

For chemical control, an initial application of a protectant fungicide should be made at bud break, followed by bimonthly applications until leaves are completely expanded. During the summer, applications every 7–14 days may be necessary to successfully manage the disease. Fungicides labeled for the control of black spot of roses in Florida are listed in Tables 1 and 2. For managing fungicide resistance, the best strategy is to rotate among products with different modes of action. All fungicides within the same group (with the same number or letter) have the same active ingredient or a similar mode of action. Fungicide resistance is usually low with multi-site inhibitor fungicides group (M).

Table 2. 

Fungicide products marketed toward homeowners for control of black spot on roses.

Trade nameActive ingredientFungicide group
Hi-Yield Captan Fungicide, Bonide Captan Fruit and OrnamentalCaptanM4
Ferti-lome Liquid Fungicide, Bonide Fung-onil Multipurpose Fungicide, Monterey Bravado Fungicide, Ortho Garden Disease ControlChlorothalonilM5
Monterey Liqui-CopCopper ammonium complexM1
Ferti-lome Blackspot Powdery Mildew Control, Hi-Yield Copper FungicideCopper hydroxideM1
Bonide Copper Dust or Spray, Dexol Bordeaux PowderCopper sulfateM1
Bonide Mancozeb FlowableMancozebM3
Spectracide Immunox Multipurpose FungicideMyclobutanil3
Bonide Rose Rx 3-in-1, Ferti-lome Triple Action Plus, Monterey 70% Neem oilNeem OilNC
Bonide RemedyPotassium bicarbonateNC
Ferti-lome Systematic Fungicide, Bonide InfusePropiconazole3
Bonide Sulfur Plant Fungicide, Ferti-lome Dusting Sulfur, Green Light Wettable Dusting Sulfur, Hi-Yield Dusting Wettable Sulfur, Safer Garden FungicideSulfurM2
Bayer Advanced Garden Disease Control for Roses, Flowers, & ShrubsTebuconazole3
Ferti-lome Halt Systemic Fungicide, Green Light Systemic FungicideThiophanate-methyl1
Ortho Rose Pride Rose & Shrub Disease ControlTriforine3
Ziram 76 DF, Ziram granufloZiramM3
Fungicide Group (FRAC Code): Numbers (1–37) and letters (M) are used to distinguish the fungicidal mode of action groups. All fungicides within the same group (with same number or letter) indicate same active ingredient or similar mode of action. This information must be considered in making decisions about how to manage fungicide resistance. M=Multi-site inhibitors, fungicide resistance is low; NC= not classified. Source: http://www.frac.info/ (Fungicide Resistance Action Committee, FRAC). Be sure to read a current product label before applying any chemicals.
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