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You spot black spots, powdery coatings, or blighted leaves on your tree, and you need a cure that works fast. The right fungicide depends on the disease and the tree type, not the brand name. Here is exactly which product matches your specific problem, based on published specs and what real buyers report.
I’m Rikta — the founder and writer behind Lawn Gear Lab. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.
Whether you are tackling fire blight (a bacterial disease that blackens branch tips) on a fruit tree or powdery mildew on an ornamental, you need a product that is labeled for trees and matched to your disease. This is your practical field guide to the best fungicide for trees available right now.
Our Picks at a Glance
How To Choose The Best Fungicide For Trees
Tree fungicides differ by active ingredient, how they move through the plant, and what they can legally claim on the label. You must match the right chemical to the right disease and the right tree.
Know Your Active Ingredient
Propiconazole is a systemic (absorbed into the tree’s tissues) that moves inside the tree for long-lasting prevention of rusts, brown patch, and powdery mildew. Chlorothalonil (found in Bonide Fung-onil) is a broad-spectrum contact chemical that stays on the surface. Copper ammonium complex works as both a fungicide and bactericide (kills bacteria too) and is organic-approved.
Systemic vs. Contact
A systemic fungicide like propiconazole or the Bacillus-based biofungicide (a product with live beneficial bacteria) is absorbed into the tree’s vascular system, protecting new growth. A contact fungicide like chlorothalonil or copper covers the leaf surface but will not cure an infection already inside the branch. For fire blight and existing internal infections, a systemic is usually necessary.
Spray, Drench, or Hose-End
Ready-to-spray (RTS) bottles attach to your garden hose and are perfect for large canopies. Concentrates must be mixed but give you many more applications per bottle. Soil drenches (pouring at the root zone) work best with systemic products so the tree pulls the chemical up into its own tissues.
Quick Comparison
| Model | Best For | Active Ingredient | Liquid Volume | Type | Amazon |
|---|---|---|---|---|---|
| Quali-Pro Propiconazole 14.3★ Best Overall | Systemic control on lawns & trees | Propiconazole 14.3% | 32 fl oz | Concentrate | Amazon |
| Bonide Revitalize BiofungicideOrganic Pick | Organic fire blight & blight control | Bacillus subtilis | 16 fl oz (conc.) | Concentrate | Amazon |
| Bonide Fung-onil | Broad-spectrum contact protection | Chlorothalonil | 16 fl oz (conc.) | Concentrate | Amazon |
| Fertilome Liquid Systemic II | Quick hose-end app for trees | Propiconazole | 32 fl oz (RTS) | Ready-to-Spray | Amazon |
| Monterey Complete Disease Control | Organic drench for leaf curl | Bacillus amyloliquefaciens | 16 fl oz (conc.) | Concentrate | Amazon |
| Garden Safe Fungicide3 | 3-in-1 organic spray | Neem Oil Extract | 128 fl oz (RTS) | Ready-to-Spray | Amazon |
| Southern Ag Liquid Copper | Bacterial & fungal on pines | Copper Ammonium Complex | 128 fl oz (conc.) | Concentrate | Amazon |
In‑Depth Reviews
1. Quali-Pro 83013366 Propiconazole 14.4 Fungicide, 32oz
Our pick — over 4.5★ from 850+ verified ratings; the strongest balance of quality and price.
The pro-grade systemic that stops the spread from inside the tree.
You get systemic protection that the tree absorbs and moves through its tissues for long-lasting control, not just surface coverage. The active ingredient is propiconazole 14.3%, a locally systemic mode of action (a chemical absorbed and transported within the plant). That means it stops rusts, brown patch, powdery mildew, anthracnose, and leaf spot from the inside out. Weighing 2 pounds with a liquid volume of 32 fluid ounces, this bottle is nearly twice the weight and holds double the volume of the 16-ounce Bonide Fung-onil concentrate. One reviewer noted that “one application of propiconazole stopped the spread immediately” on Bermuda grass disease, and another says the bottle will probably last them 4-5 years with yearly applications. The microemulsion formulation (an oil-based liquid that mixes easily) means less odor and better tank stability. It is labeled for tree injection, nursery, landscape, turf, and golf courses, giving it real professional credentials.
Propiconazole systemic control
- Systemic action moves inside the tree for prevention
- Broad label: trees, shrubs, turf, ornamentals
- One bottle covers a large area over many seasons
Requires precise mixing
- You must mix it yourself (not RTS)
- Some owners mention needing yearly reapplication
broad spectrum: Homeowners with large properties who want a professional-grade systemic that lasts multiple seasons.
limited curative: This is a chemical concentrate — follow PPE (personal protective equipment) and mixing instructions carefully; not for organic gardening.
2. Bonide Revitalize Biofungicide, 16 oz Concentrate
A biofungicide that triggers the tree’s own immune response.
If you grow organic fruit or vegetable trees and want to avoid synthetic chemicals, this Bonide product uses a live bacterium (Bacillus subtilis) that triggers an immune response in the plant to control diseases like blight, powdery mildew, and anthracnose. Unlike the Quali-Pro synthetic systemic, this biofungicide works with the tree’s biology. It is approved for organic gardening and can be used up until the day of harvest. One buyer with mature pear trees suffering from fire blight reported: “After using this for about a month & applying every 3-4 days as a soil drench, the trees are starting to show signs of rebounding — new leaves, no more black leaves, etc.” The concentrate bottle holds 16 fluid ounces, half the volume of the Quali-Pro 32-ounce bottle, so this cycle is for the organic gardener who values biological control over synthetic speed. It can be applied as either a foliar spray or a soil drench.
Revitalize biofungicide
- OMRI-listed (certified by the Organic Materials Review Institute) for organic gardening
- Can be used right up to harvest day
- Works as a soil drench to treat roots
Not for severe cases
- Needs frequent application (every 3-4 days initially)
- Slower acting than synthetic systemic fungicides
preventative use: You grow organic fruit or nut trees and want a harvest-safe, biological approach that strengthens the tree over time.
heavy infections: You need immediate knockdown of an aggressive, fast-spreading infection — a synthetic systemic is faster.
3. Bonide Fung-onil Multi-Purpose Fungicide, 16 oz Concentrate
The classic contact spray that covers a huge range of tree diseases.
This is a budget-friendly preventative option if you want broad coverage against many diseases. Chlorothalonil is among the most widely used broad-spectrum contact fungicides (a chemical that stays on the leaf surface as a protective barrier) in home gardening. This Bonide concentrate packs it in a 16-ounce bottle weighing just 1 pound — half the weight of the Quali-Pro concentrate. It controls leaf spot, rust, blight, mildew, scab, and mold on trees, shrubs, ornamentals, vegetables, and fruits. Because it is a contact fungicide, it stays on the leaf surface rather than moving inside the plant, so it is excellent for prevention and early-stage treatment. However, an established internal infection may need a systemic. Customers note that “fungus cleared for 2 months then returned late season.” The concentrate leaves a white residue on plants that washes off easily.
Fung-onil multi-purpose
- Very broad disease label (blight, mildew, scab, rust)
- Affordable price point per application
- Mixes easily and clings to foliage
Residue on plants
- Contact-only — will not cure internal infection
- Leaves visible white residue on leaves
- Some reviewers point out disease returns late season
wide coverage: A budget-friendly preventative spray for ornamental trees and shrubs where you want broad coverage against many diseases.
edible crops: If your tree already has internal disease or fire blight, choose a systemic product instead.
4. Fertilome (11380) Liquid Systemic Fungicide II RTS (32oz)
Screw onto your hose and walk the yard — systemic control without mixing.
If you do not want to measure concentrates or clean sprayers, this is your pick. The Fertilome Liquid Systemic Fungicide II comes in a ready-to-use 32-ounce spray bottle that attaches directly to your garden hose. It is a systemic fungicide (propiconazole-based) that controls Take All Patch, Brown Patch, Dollar Spot, and Leaf Spot on lawns and trees. At 32 fluid ounces, it holds the same unit count as the Quali-Pro but is ready-to-spray — you do not dilute it. Shoppers say dramatic results: “Fertilome fungicide cured Fire Blight on Crimson Maple after three biweekly hose-end sprays; tree now lush and healthy.” Another buyer said it stopped yellowing leaves on mature Live Oaks after just one treatment. Unlike the Bonide concentrates that require mixing and measuring, this RTS bottle is grab-and-go. For best results, apply early in the growing season.
Liquid systemic ready
- No mixing required — hose-end application
- Systemic action for fire blight and leaf spot
- Reportedly works in one to three treatments
Smaller bottle size
- More expensive per ounce than concentrates
- One bottle covers a limited area
quick application: Homeowners who want systemic treatment for a few trees without buying a sprayer or mixing chemicals.
large areas: Heavy infestations may need multiple applications, and you get fewer total treatments per dollar than a concentrate.
5. Monterey Complete Disease Control Bundled with Measuring Spoon, 1 Pint
A biological drench that colonizes root hairs to stop disease at the source.
You get an organic, root-level approach to disease prevention on fruit and nut trees. This Monterey product uses Bacillus amyloliquefaciens, a beneficial bacterium that colonizes the root hairs of your trees. This biological approach prevents the establishment of disease-causing fungi and bacteria from the ground up. It is OMRI Listed for organic gardening and can be used on ornamental trees, nuts, fruits, vegetables, and houseplants. The 16-fluid-ounce concentrate bottle comes bundled with a measuring spoon, so you do not have to guess the mix rate. Buyers in the south call it a “life saver for tomato plants,” and one buyer mentioned it is “outstanding for peach leaf curl” when applied multiple times in spring as leaves emerge. Unlike the synthetic systemics, this is a biological product that requires consistent application — it controls rather than nukes the disease.
Complete disease bundle
- Organic-friendly and OMRI Listed
- Colonizes roots for internal protection
- Effective as a drench or foliar spray
Measuring cup included
- Controls, but does not cure, existing infections
- Requires multiple applications; slower-acting
- Health warning on label for mixing
convenient kit: You want an organic, root-level approach to disease prevention on fruit and nut trees, especially for peach leaf curl.
extra cost: Your tree has an active, fast-moving infection that needs immediate chemical control — this is a preventative or slow-control product.
6. Garden Safe Brand Fungicide3, 1 Gallon
One sprayer jug that kills fungus, aphids, and mites at the same time.
If your tree has a combined problem — fungus plus insect pests — this Garden Safe product is a triple threat. It is a fungicide, insecticide (kills insects), and miticide (kills mites) all in one ready-to-spray gallon jug (128 fluid ounces). The active ingredient is clarified hydrophobic extract of neem oil, which is organic-approved and controls black spot, rust, powdery mildew, aphids, whiteflies, and spider mites. The built-in sprayer attaches to your hose, so you treat large trees without hauling buckets of mixed chemicals. Buyers report it is “absolutely amazing stuff,” effective against mildew on hibiscus, roses, tomatoes, and blueberries when used weekly. One reviewer warned that the included sprayer is frustrating — “you have about 4 inches of coiled product to reach out to your plant” — so you may want a separate sprayer. Unlike the synthetic systemics above, this is a contact product that needs thorough coverage of all leaf surfaces.
Fungicide3 gallon
- Fungicide, insecticide, and miticide in one jug
- Ready-to-spray — no mixing
- Large 1-gallon jug covers a lot of trees
Dilution required
- Sprayer design is short and awkward
- Can burn plants if used at full strength in sun
- Contact-only; no systemic action inside tree
large volume: Organic gardeners with pest-and-fungus problems on ornamentals and fruit trees, who want one product for both issues.
storage space: It is a contact spray, not a cure for internal tree infections, and the included sprayer may frustrate you.
7. Southern Ag Liquid Copper Fungicide, 1 Gallon
A heavy-duty copper concentrate for fungus and bacteria on large trees.
When you need a broad-spectrum solution that handles both fungal diseases and bacterial infections (like fire blight or bacterial leaf spot), liquid copper is your answer. This Southern Ag product contains 31.4% Copper Ammonium Complex (8% metallic copper equivalent — the portion that is pure copper) in a 1-gallon jug. It is a concentrate that works with hose-end sprayers and is labeled for control of moss, algae, and a wide range of tree diseases. Weighing 9 pounds, this is the heaviest bottle in the lineup — significantly heavier than the 2-pound Quali-Pro bottle. Buyers have used it for years on pine trees: “Product works well to prevent fungus damage to my pine trees. Have used it for years and my trees look great compared to my neighbors.” One commercial grower called it the best product for leaf blight on peppers. It is also 100% organic and non-toxic to animals and humans when used per label. However, some recent owners mention receiving a 27% strength bottle despite the listed 31.4%, so check your bottle’s label.
Liquid copper fungicide
- Kills both fungal and bacterial diseases
- Organic-approved and safe around pets
- Large 1-gallon concentrate goes a long way
Stains surfaces
- Copper can build up in soil over time
- Some bottles may have lower copper concentration than advertised
- Do not tank mix with other chemicals (may burn plants)
organic option: Owners of large pine, fruit, or nut tree groves who want an organic, broad-spectrum product that also handles bacterial infections like fire blight.
phytotoxicity risk: You need a fast-acting systemic cure for an established internal tree infection — copper is a preventative contact product and may not cure what is already inside.
Understanding the Specs
Active Ingredient
This is the chemical or biological agent that actually kills the fungus. Propiconazole is a systemic triazole (a class of fungicide that disrupts fungal cell membranes) that stops fungal cell growth by disrupting the cell membrane. Chlorothalonil is a broad-spectrum contact that prevents spore germination (the growth of spores into new fungi) on leaf surfaces. Bacillus subtilis and B. amyloliquefaciens are live beneficial bacteria that trigger the tree’s own immune defenses. Copper ammonium complex damages fungal and bacterial proteins on contact. The best tree fungicide for you depends entirely on whether your tree needs surface protection or internal treatment.
Systemic vs. Contact
A systemic fungicide (like propiconazole or the Bacillus biofungicides) is absorbed into the tree’s vascular system. It moves up through the xylem (water-conducting tissue) to protect new growth and existing leaves from inside. A contact fungicide (like chlorothalonil or copper) stays on the outside and must cover every surface to be effective. Rain can wash off contact fungicides, while systemics are rainfast (resistant to rain) after they dry and are absorbed. For fire blight, root rots, and internal cankers (dead areas on branches), you almost always need a systemic.
Concentrate vs. Ready-to-Spray
Concentrates (like the Quali-Pro, Bonide, Monterey, and Southern Ag options) require you to mix with water in a sprayer at a specific rate. They are far more cost-effective per gallon of spray, and one 16-ounce concentrate bottle can make many gallons. Ready-to-spray (RTS) bottles (like the Fertilome and Garden Safe options) attach to your hose or have a built-in sprayer — you turn it on and walk. RTS is more expensive per ounce but requires zero measuring and zero cleanup. For a single tree, RTS is fine. For a whole orchard or large property, a concentrate saves money.
Liquid Volume
Measured in fluid ounces (fl oz; a volume measurement, about 30 ml per ounce). A larger bottle does not necessarily mean more applications — it depends on the dilution rate. For example, a 16-ounce concentrate that mixes at 2 oz per gallon gives you 8 gallons of spray. A 32-ounce RTS bottle is used at full strength, so it covers a much smaller area. The 9-pound Southern Ag copper jug at 128 fluid ounces is a concentrate that makes many gallons of spray. Always check the label for how many gallons each ounce of concentrate will treat before comparing bottle sizes.
FAQ
Can I use the same fungicide on my lawn and my trees?
How often should I spray my trees with fungicide?
Will fungicide hurt my tree’s fruit or vegetables?
What is the difference between a soil drench and a foliar spray?
Can I mix fungicide with insecticide in the same sprayer?
How do I know if my tree has a fungal or bacterial problem?
Can I use tree fungicide on newly planted trees?
Why does my fungicide leave white residue on leaves?
How long does a bottle of concentrate last in storage?
Is organic fungicide as effective as synthetic on trees?
Final Thoughts: The Verdict
For most people, the fungicide for trees winner is the Quali-Pro Propiconazole 14.3 because it combines professional-grade systemic action, a wide disease label for trees, and outstanding value per bottle — one reported treatment stops spread immediately and the bottle lasts years. If you want an organic option for fruit tree fire blight, grab the Bonide Revitalize Biofungicide. And for a ready-to-spray convenience with no mixing required, the Fertilome Liquid Systemic II has reportedly cured fire blight on maples with just three hose-end applications.
How We Picked
We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.
Sources & Methodology
Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of July 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.
As an Amazon Associate, Lawn Gear Lab earns from qualifying purchases. This does not affect which products we feature.