Myclobutanil is the homeowner's go-to systemic fungicide for fruit trees, roses, and ornamentals. It controls black spot, powdery mildew, apple scab, rust, and many other common garden diseases. Absorbed by the plant for inside-out protection.
Rose black spot, powdery mildew (roses, vegetables, ornamentals), apple scab, cedar-apple rust, brown rot (stone fruits), leaf spot diseases, anthracnose. Excellent broad-spectrum ornamental and fruit tree fungicide. Not typically used on lawns (propiconazole is preferred for turf).
Spectracide Immunox (most popular consumer brand), Monterey Fungi-Max, Ferti-lome F-Stop, Rally (professional), Nova (professional). Available as ready-to-spray and concentrate formulations.
Low acute toxicity. Wear gloves during mixing. Pre-harvest interval varies by crop — check label carefully for edible crops. Keep pets off treated ornamentals until spray has dried. Do not apply to edible crops within the specified PHI (pre-harvest interval).
For roses: Begin applications in spring before black spot appears. Apply every 14 days during the growing season. Myclobutanil is one of the most effective rose fungicides available to homeowners.
For apple scab: Critical timing — apply at green tip stage and continue through petal fall. Once scab lesions are visible, curative activity is limited. Prevention is key.
Rain resistance: Once dried (2 hours), myclobutanil is rain-fast. It's also systemic, so it protects new growth between applications. This is a major advantage over copper-based fungicides which wash off.