Best Fungus Killer for Plants: 10 Fungicides for Gardens, Roses and Shrubs

Not every spotted leaf is a fungus, and not every fungus needs the same product. Powdery mildew, black spot, rust and root rot are all fungal, but the sprays that suit them are not the same.

The best fungus killer for plants is the one that lists your disease, your plant type and a form you will actually use. The Ortho MAX Garden Disease Control is a concentrate for mixed gardens. The Bonide Copper Fungicide RTU, 2 Pack is a ready-to-use copper spray approved for organic gardening. The BioAdvanced Disease Control 32 oz is a systemic for roses and shrubs.

We compared 10 fungicides by type, form, size and the diseases and plants each listing names. Every claim below comes from the listing. Read the label before you spray, and check the wait time before you eat anything you have treated.

Gardenbine earns a commission from qualifying Amazon purchases made through links on this page, at no extra cost to you. Product details come from the manufacturers’ listings.

On this page

1. Compare Plant Fungicides by Type, Form, Size and Key Claim
2. Detailed Reviews: Best Fungus Killer for Plants
3. Name the Problem Before You Pick a Product
4. Read the Label for Plants, Timing and Harvest Wait
5. How to Choose a Fungicide for Your Plants
6. Which Fungus Killer Should You Choose?
7. Frequently Asked Questions
8. Final Verdict

Compare Plant Fungicides by Type, Form, Size and Key Claim

Detailed Reviews: Best Fungus Killer for Plants

1. Ortho MAX Garden Disease Control Concentrate, 16 fl. oz. (Best overall garden fungicide concentrate)

• 16 fl ozSize
• 64 galMakes up to
• Rust, blight, mildewListed diseases
• Veg, flowers, treesPlants

Best for: a mixed garden with vegetables, flowers and shrubs

Why it ranks #1: It makes the most spray per bottle of any concentrate here and lists the widest range of plant types.

Ortho lists this as a garden disease control concentrate that stops and prevents diseases including rust, leaf spot, blight, powdery mildew and fruit rot. The listing says it makes up to 64 gallons of diluted spray.

It names vegetables, flowers, shrubs, shade trees and fruit trees. It is a concentrate, so you mix it with water. Follow the label for rates and the wait time before you harvest.

Skip it if you want something ready to spray; the Bonide Copper Fungicide RTU, 2 Pack is trigger-ready.

2. Bonide Captain Jacks Copper Fungicide, 32 oz Ready-to-Use Spray, Pack of 2 (Best organic ready-to-use copper spray)

• 32 ozBottle
• 2Pack
• OrganicApproved
• Up to harvestUse window

Best for: vegetables and fruit where you want an organic spray and a short wait to harvest

Why it ranks #2: It combines a ready-to-use trigger bottle with organic approval and use up to harvest day.

Bonide lists a ready-to-use liquid copper fungicide in a trigger spray bottle, sold as a pack of 2 bottles of 32 oz. The listing says it is approved for organic gardening and can be used up until the day of harvest.

Listed diseases include blight, black spot, powdery mildew and peach leaf curl. You shake it, then thoroughly apply it to the plant and leaves. Check the label for full directions.

Skip it if you want a concentrate; the Ortho MAX Garden Disease Control makes up to 64 gallons.

3. Natria Disease and Fungus Control Spray with Copper Fungicide, 24 fl oz (Best OMRI listed copper spray)

• 24 fl ozBottle
• OMRIListed
• Day of harvestLast use
• Indoor and outdoorUse

Best for: edible plants, houseplants and home greenhouses

Why it ranks #3: It lists indoor, outdoor and greenhouse use and OMRI listing in one ready-to-use bottle.

Natria lists a ready-to-use copper spray that controls powdery mildew, rust, black spot, fruit rot, downy mildew and late blight. The listing says it is OMRI listed for organic and hydroponic gardening and can be applied up to and including harvest day.

The listing names home gardens, indoor plants and home greenhouses, and says thorough coverage is essential.

Skip it if you want a two-pack; the Bonide Copper Fungicide RTU, 2 Pack is sold as two.

4. BioAdvanced Disease Control for Roses, Flowers and Shrubs Concentrate, 32 oz (Best systemic concentrate for roses and shrubs)

• 32 ozSize
• 42 galMakes up to
• 2 weeksProtection
• RainproofOnce dry

Best for: roses, flowers and shrubs that get black spot and mildew

Why it ranks #4: It is a systemic with a stated protection window and a stated spray yield.

BioAdvanced lists a systemic formula that cures and prevents listed diseases on roses, flowers, shrubs and houseplants treated outside. Diseases named include black spot, powdery mildew, crabapple scab and boxwood blight.

The listing says protection is rainproof once dry and lasts up to 2 weeks, and a bottle makes up to 42 gallons. You mix it with water and use a coarse spray.

Skip it if you grow vegetables; the Ortho MAX Garden Disease Control lists them.

5. Garden Safe Brand Fungicide3 with Neem Oil, 32 Oz (Best 3-in-1 neem option)

• 32 ozSize
• 3-in-1Uses
• Neem oilActive
• Black spot, rustDiseases

Best for: roses, flowers, vegetables and houseplants with both fungus and insects

Why it ranks #5: It treats fungus and insects in one product, but its listing does not say if it is ready to use or a concentrate.

Garden Safe lists a product that is a fungicide, insecticide and miticide, with the active ingredient clarified hydrophobic extract of neem oil. It controls black spot, rust, powdery mildew and other listed fungal diseases.

It also lists aphids, whiteflies and spider mites. The listing names roses, flowers, houseplants, ornamental trees and shrubs, fruits and vegetables for organic gardening.

Skip it if you want copper; the Bonide Copper Fungicide RTU, 2 Pack and Natria Disease and Fungus Control are copper.

6. Bonide Captain Jacks Neem Max, 32 oz Ready-to-Use Spray, Cold Pressed Neem Oil (Best cold pressed neem spray)

• 32 ozBottle
• 4-in-1Uses
• Cold pressedNeem oil
• OrganicApproved

Best for: indoor and outdoor plants with both disease and pests

Why it ranks #6: It is a ready-to-use neem spray with four listed uses and organic approval.

Bonide lists a 4-in-1 insecticide, fungicide, miticide and nematicide in a trigger spray bottle, approved for organic gardening, with cold pressed neem oil as the active ingredient. The listing says it kills insect eggs, larvae and adults, including aphids, mites, beetles and caterpillars.

It also covers listed fungal diseases indoors and outdoors, and you can apply it as a spray or drench. Read the label before use.

Skip it if you want a stronger disease concentrate; the Ortho MAX Garden Disease Control makes up to 64 gallons.

7. Daconil Fungicide Concentrate RFID 16 Fluid Ounces (Best for a wide disease list)

• 16 fl ozSize
• 65+Diseases listed
• Rain-proofProtection
• Veg, flowers, treesPlants

Best for: gardens with tomato blight, anthracnose or powdery mildew

Why it ranks #7: It lists the longest disease range, but gives little other detail.

The listing says this concentrate controls, stops and prevents over 65 diseases including tomato blight, anthracnose, Fusarium wilt, mold and powdery mildew. It names vegetables, flowers, fruit and shade trees.

The listing says it gives rain-proof protection. It does not list the active ingredient or the coverage per bottle, so check the label.

Skip it if you want a stated yield; the Ortho MAX Garden Disease Control says 64 gallons.

8. Bonide Infuse Systemic Disease Control, 16 oz Concentrated Solution (Best systemic for lawns and ornamentals)

• 16 ozBottle
• 30+Diseases listed
• 4 weeksProtection
• 3,200 sq ftPer quart

Best for: lawns, roses, trees and shrubs together

Why it ranks #8: It covers turf and ornamentals and lists up to 4 weeks of protection.

Bonide lists a broad spectrum systemic fungicide for turf and ornamentals, effective on over 30 listed diseases including rust, blight, powdery mildew and leaf spot. When used as directed, the listing says one quart treats up to 3,200 sq ft and lasts up to 4 weeks.

This bottle is 16 oz, so check coverage on the label. You mix the concentrate with water and apply after mowing.

Skip it if you want vegetables; the Ortho MAX Garden Disease Control lists them.

9. Monterey Garden Phos Fungicide, 16 fl oz with Measuring Spoon (Best for root rot and soil drench)

• 16 fl ozSize
• SystemicType
• Drench or sprayUse
• SpoonIncluded

Best for: root and collar rot, fire blight and Phytophthora problems

Why it ranks #9: It targets root and collar diseases and can be a drench, spray or bark treatment.

Monterey lists a systemic fungicide for root rot, downy mildew, fire blight, sudden oak death, Phytophthora and Pythium diseases. It can be a soil drench, foliar spray or basal bark application.

It lists ornamentals, trees, vegetables, fruits and bedding plants, and says to use a pump sprayer and follow label mixing steps. A measuring spoon is included.

Skip it if you mostly see leaf spots; the Ortho MAX Garden Disease Control lists leaf spot and rust.

10. Southern Ag Garden Friendly Biological Fungicide, 16oz (Best biological option)

• 16 ozSize
• BiologicalType
• Garden friendlyTitle claim
• Not listedDetails

Best for: gardeners who want a biological product

Why it ranks #10: Its listing gives only a name and size, so the least can be checked about it.

The listing gives a name, a 16 oz size and the words garden friendly biological fungicide. It lists no diseases, plant types or directions.

Use the product page and label for what it controls, how to mix it and where it can be used.

Skip it if you want a disease list; the Ortho MAX Garden Disease Control names many.

Name the Problem Before You Pick a Product

A fungicide only helps if the problem is fungal. Leaf spots, white powder, orange pustules and black marks are common signs, but overwatering, poor airflow and insects can look similar. Remove badly infected leaves first and look at the pattern of damage.

Then match the product to the disease. The Bonide Infuse Systemic lists lawn and ornamental diseases, the Monterey Garden Phos lists root and collar rot, and the BioAdvanced Disease Control 32 oz lists black spot and powdery mildew. A broad concentrate like the Ortho MAX Garden Disease Control lists rust, leaf spot, blight and powdery mildew.

Read the Label for Plants, Timing and Harvest Wait

The label is the rule. It tells you which plants the product is approved for, how much to mix and how long to wait before harvest. Some listings, like the Bonide Copper Fungicide RTU, 2 Pack and Natria Disease and Fungus Control, say you can use them up to harvest day, while others do not state a wait time.

Do not spray in hot midday sun or in wind. Cover both sides of the leaves. Spraying too often or at too strong a rate can harm plants. Wear gloves and eye protection, and keep pets and children away until the spray dries.

A fungicide works best as part of a plan: water at the base, space plants for airflow and clear fallen leaves.

How to Choose a Fungicide for Your Plants

Type

Copper like the Bonide Copper Fungicide RTU, 2 Pack and Natria Disease and Fungus Control is a classic organic choice. Neem like the Garden Safe Fungicide3 with Neem Oil and Bonide Neem Max RTU 32 oz also treats insects. Systemics like the BioAdvanced Disease Control 32 oz and Bonide Infuse Systemic move into the plant.

Form

Ready to use bottles like the Bonide Copper Fungicide RTU, 2 Pack need no mixing. Concentrates like the Ortho MAX Garden Disease Control and Daconil Fungicide Concentrate make many gallons of spray but you mix them.

Plants and diseases

Check the list. The Daconil Fungicide Concentrate lists over 65 diseases, and the Monterey Garden Phos lists root rot.

Organic use

The Natria Disease and Fungus Control is OMRI listed and the Bonide Copper Fungicide RTU, 2 Pack is approved for organic gardening.

Which Fungus Killer Should You Choose?

• If you want the best all-round concentrate, choose the Ortho MAX Garden Disease Control, because it makes up to 64 gallons.
• If you want organic copper in a trigger bottle, choose the Bonide Copper Fungicide RTU, 2 Pack, because it is approved for organic gardening.
• If you want OMRI listed copper, choose the Natria Disease and Fungus Control, because it lists indoor and outdoor use.
• If you grow roses and shrubs, choose the BioAdvanced Disease Control 32 oz, because it is a systemic with up to 2 weeks of protection.
• If you want fungus and insect control in one, choose the Garden Safe Fungicide3 with Neem Oil, because it has neem oil.
• If you want ready-to-use neem, choose the Bonide Neem Max RTU 32 oz, because it is cold pressed.
• If you want a long disease list, choose the Daconil Fungicide Concentrate, because it lists over 65 diseases.
• If you treat lawns and ornamentals, choose the Bonide Infuse Systemic, because it is a systemic for turf.
• If you fight root rot, choose the Monterey Garden Phos, because it can be a soil drench.
• If you want a biological product, choose the Southern Ag Biological Fungicide, because it is sold as one.

Frequently Asked Questions

What is the best fungus killer for plants?

For a mixed garden, the Ortho MAX Garden Disease Control is the best pick here, with up to 64 gallons per bottle and many plant types listed. For organic gardens, the Bonide Copper Fungicide RTU, 2 Pack and Natria Disease and Fungus Control are copper sprays.

Is copper or neem better for plant fungus?

Copper like the Bonide Copper Fungicide RTU, 2 Pack is a fungicide. Neem like the Bonide Neem Max RTU 32 oz treats fungus and insects. Choose copper for disease, and neem if you also have pests.

What does a systemic fungicide do?

It moves inside the plant. The BioAdvanced Disease Control 32 oz lists systemic protection that lasts up to 2 weeks, and the Bonide Infuse Systemic lists up to 4 weeks. Follow label timing.

Can I spray fungicide on vegetables?

Only products that list vegetables on the label. The Ortho MAX Garden Disease Control, Bonide Copper Fungicide RTU, 2 Pack and Natria Disease and Fungus Control name vegetables or edible plants. Check the harvest wait time on the label.

How often should I spray?

Follow the label. Listings give windows like 2 weeks for the BioAdvanced Disease Control 32 oz and 4 weeks for the Bonide Infuse Systemic, but real timing depends on the rate and weather.

Does a fungicide fix root rot?

Root rot often comes from wet soil. The Monterey Garden Phos lists root and collar rot and can be a drench, but fix drainage and watering as well.

Final Verdict

The Ortho MAX Garden Disease Control is the best fungus killer for plants in this guide. It makes up to 64 gallons per bottle and lists rust, leaf spot, blight and powdery mildew on vegetables, flowers, shrubs and trees. For organic gardens, the Bonide Copper Fungicide RTU, 2 Pack is a ready-to-use copper spray approved for organic use. Before you buy, name your plant problem and read the label for plants and harvest wait.

See the Ortho MAX Garden Disease Control on Amazon