Disease - Vegetable

Home Vegetable Garden Fungicides

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UW Plant Disease Facts

 

Authors:   Amanda Gevens, UW-Madison Plant Pathology with contributions by UW-Madison Plant Pathology undergraduates Ken Cleveland and Lauren Thomas
Last Revised:   04/10/2026
D-number:   D0062
 

Diseases of vegetable plants can pose a challenge for the home gardener.  Typically, cultural methods are the preferred options for disease management in home vegetable gardens.  Cultural methods include proper site selection, plant spacing, staking, watering, fertilization, and perhaps most importantly, use of disease-resistant vegetable cultivars.  However, if diseases become especially problematic, fungicide treatments are also an option for home gardeners.

This guide is intended to help identify some of the common, and most suitable, fungicides available for disease control in home vegetable gardens.  All of the fungicides listed on this fact sheet have been found on shelves at southern Wisconsin home garden centers.  This listing is not intended to be exhaustive, but references fungicides that, when used properly, can be effective in controlling the most common diseases of vegetables grown in home gardens.  When selecting a product from this list, be sure to note the product name carefully, as several products can have very similar names and contain similar active ingredients.  Check that the active ingredient on the label of the product that you select is the ingredient that you are looking for.  Also, be sure to read and follow all label instructions of the fungicide that you select to ensure that you use the product in the safest and most effective manner possible.

Asparagus

Rust

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • mancozeb (Mancozeb Flowable)
            • myclobutanil (Spectracide Immunox)
            • propiconazole (Monterey Fungi Fighter, Infuse)
            • tebuconazole (Bayer Advanced 3 in 1,
              Bayer Advanced Disease Control)

Bean

Rust

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • myclobutanil (Spectracide Immunox)
            • propiconazole (Monterey Fungi Fighter, Infuse)
            • tebuconazole (Bayer Advanced 3 in 1, Bayer Advanced Disease Control)

Carrot

Alternaria leaf blight

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)
            • propiconazole (Monterey Fungi Fighter, Infuse)

Cercospora leaf blight

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)
            • propiconazole (Monterey Fungi Fighter, Infuse)

Cucurbits (cucumber, melon, squash)

Downy mildew

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)
            • mancozeb (Mancozeb Flowable)
            • phosphorous acids (Excel LG-Systemic Fungicide)

Powdery Mildew

Active Ingredients (Brand Names)

            • myclobutanil (Spectracide Immunox)
            • neem oil* (70% Neem Oil, Garden Safe,
              Natural)
            • other plant-based oils* (Vegetable Pharm,
              SNS 244 All Natural, Organocide, Oleotrol M)
            • potassium bicarbonate* (Green Cure Organic Fungicide)
            • propiconazole (Monterey Fungi Fighter, Infuse)
            • sulfur* (Dusting sulfur, Earth Tone 3 in 1,
              Safer Garden Fungicide)
            • tebuconazole (Bayer Advanced 3 in 1,
              Bayer Advanced Disease Control)

Onion

Downy mildew

Active Ingredient (Brand Name)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)
            • mancozeb (Mancozeb Flowable)
            • phosphorous acids (Excel LG-Systemic Fungicide)

Leaf blight

Active Ingredient (Brand Name)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • mancozeb (Mancozeb Flowable)

Purple blotch

Active Ingredient (Brand Name)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • mancozeb (Mancozeb Flowable)

Pepper

Anthracnose

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)

Potato

Early blight

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)
            • mancozeb (Mancozeb Flowable)

Late blight

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)
            • mancozeb (Mancozeb Flowable)

Sweet corn

Fungal foliar diseases

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • mancozeb (Mancozeb Flowable)
            • propiconazole (Monterey Fungi Fighter, Infuse)
            • tebuconazole (Bayer Advanced 3 in 1,
              Bayer Advanced Disease Control)

Rust

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • mancozeb (Mancozeb Flowable)
            • propiconazole (Monterey Fungi Fighter, Infuse)
            • tebuconazole (Bayer Advanced 3 in 1,
              Bayer Advanced Disease Control)

Tomato

Early blight

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)
            • mancozeb (Mancozeb Flowable)

Late blight

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)
            • mancozeb (Mancozeb Flowable)

Septoria leaf spot

Active Ingredient (Brand Names)

            • chlorothalonil (Daconil, Fung-onil,
              Ortho Max Disease Control)
            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)
            • mancozeb (Mancozeb Flowable)

Vegetables (general)

Damping-off

Active Ingredient (Brand Names)

            • Streptomyces lydicus* (Actino-Iron, Actinovate)

Root rot

Active Ingredient (Brand Names)

            • Streptomyces lydicus* (Actino-Iron, Actinovate)

Bacterial diseases

(bean bacterial blight, cabbage black rot, cucumber angular leaf spot, onion bacterial blight, pepper bacterial spot, potato blackleg, tomato bacterial spot)

Active Ingredient (Brand Names)

            • copper* (Copper Fungicide, Copper Soap,
              Dragon Dust, Earth Tone,
              Garden Dust)

Viral diseases

(cucumber mosaic virus, tobacco mosaic virus, tomato spotted wilt virus)

Active Ingredient (Brand Names)

            • none (None)

*Active ingredients generally considered ‘organic’.  Certified organic growers must use pesticides approved by their organic certifying agency.

For more information on home vegetable garden fungicides: 

Contact the University of Wisconsin Plant Disease Diagnostics Clinic (PDDC) at 608-262-2863 or pddc@wisc.edu.

This Fact Sheet is also available in PDF format:

© 2012-2026 the Board of Regents of the University of Wisconsin System doing business as University of Wisconsin-Madison Division of Extension.

An EEO/Affirmative Action employer, University of Wisconsin-Madison Division of Extension provides equal opportunities in employment and programming, including Title IX and ADA requirements. This document can be provided in an alternative format by calling Brian Hudelson at 608-262-2863 (711 for Wisconsin Relay).

References to pesticide products in this publication are for your convenience and are not an endorsement or criticism of one product over similar products. You are responsible for using pesticides according to the manufacturer’s current label directions. Follow directions exactly to protect the environment and people from pesticide exposure. Failure to do so violates the law.

Thanks to Russell Groves, Stephen Jordan, James Kerns and Patti Nagai for reviewing this document.

A complete inventory of UW Plant Disease Facts is available at the University of Wisconsin-Madison Plant Disease Diagnostics Clinic website. (https://pddc.wisc.edu) 

Submit additional lawn, landscape, and gardening questions at the Ask a Gardening Question page (https://hort.extension.wisc.edu/ask-a-gardening-question/) of the University of Wisconsin-Madison Division of Extension Horticulture website.