When you first set out to grow apples, you probably pictured a handsome, sturdy little tree. You likely thought about plucking bright, crispy, deliciously sweet apples from its branches. Maybe you thought about the apple pies you’d bake or the look on your neighbor’s face when you handed them a bag filled with your amazing, homegrown fruit.
You may not have considered, though, that all the painstaking care and attention you put into raising your apple tree could be thwarted by a fungal pathogen, leaving you wondering if hope for a yearly harvest of apples is lost.
Fear not. Your apple tree can still be successful. Preventative action with the right fungicide can prevent a fungal disease from appearing at all. And, if you act swiftly, some fungicides can even tackle fungal infections already plaguing your tree.
To help you avoid a tree loss situation, we’re going to talk about 8 options for the best fungicide for apple trees.
Our Top Picks
Best Systemic Fungicide:
Hi-Yield Vegetable, Flower, Fruit and Ornamental Fungicide
Best Contact Fungicide:
Southern Ag Captan 50W Fungicide
Best Small Sprayer for 1-2 trees:
CHAPIN 2 Gallon Sprayer
Introduction to Fungicides
So, you’d like to protect your tree from a fungal infection but don’t know the differences between them. Let’s start with the different kinds of fungicides that are on the market.
Categories of Fungicides
Fungicides fall into two general categories: contact/protectant and systemic.
Contact (or protectant) fungicides only protect the areas where the spray touches the surface of the plant. These fungicides do not penetrate the plant and they require careful spraying to ensure all plant surfaces have been covered. These fungicides need to be repeatedly sprayed because they will wash off with rain and new growth is not protected.
Systemic fungicides move throughout the plant and are capable of protecting more than just the location that was sprayed. Unlike contact/protectant fungicides, systemic fungicides can be curative, stopping and reversing infections after they have begun.
Organic and Inorganic
Perhaps one of the most confusing and frustrating things you encounter as you search for the best fungicide for your apple tree is that the term “organic” doesn’t always mean the same thing to everyone.
The chemistry definition and the USDA definition of “organic” differ. So, when you hear or read that a fungicide is “organic” or “inorganic,” it might help to think “naturally occurring” or “synthetic,” instead. Hence, you may encounter a copper or a sulfur fungicide that’s still labeled as organic.
Which Type Makes the Best Fungicide for Apple Trees
Unfortunately, there isn’t one best fungicide for apple trees because – in addition to varying mechanisms of action – factors such as which type of fungal infection you’re trying to guard against, environmental conditions, local climate, and your own personal considerations are all important.
In our list of best fungicides for apple trees, we’ll provide our pick for the best fungicide within various categories and give some information on each category.
8 Best Fungicides for Apple Trees
Best Systemic Fungicide
Hi-Yield Vegetable, Flower, Fruit and Ornamental Fungicide
Chlorothalonil is a chemical used as a broad-spectrum fungicide that’s sometimes sold under names such as Bravo or Daconil. It’s effective on numerous types of plants including orchard crops such as apple trees. Some chlorothalonil fungicides are specially formulated so that they’re resistant to the weather. This chlorothalonil fungicide by Hi-Yield is systemic and is both preventative and curative.
- Effective on many different fungal pathogens
- Offers weather-resistant protection
- Can be used on numerous kinds of plants
- One of the most widely used kinds of fungicides
- Preventative and curative
- Toxic to people, birds, and aquatic life
- Poses moderate ecological risk, particularly if it gets in water
Best Protectant Contact Fungicide
Southern Ag Captan 50W Fungicide
Captan is a form of dicarboximide and totally synthetic. It’s effective against diseases such as cedar apple rust, black, white, bitter, and blossom end rot, early and late blight, brooks spot, and downy mildew scab. However, it’s not ideal for treating fire blight but it is compatible with many other fungicides.
Although it’s non-organic, it isn’t particularly toxic in low doses and breaks down quickly in the soil. The Hi-Yield captan fungicide comes in powder form. While this does require extra precaution to avoid inhaling it, it allows additional versatility in how you’re able to use it. It can be applied both as a powder and in a solution. As always, read and follow label instructions diligently.
You can find this captan fungicide from Nature Hills Nursery.
- Breaks down quickly in the soil
- Usable as both a dry powder and in a liquid solution
- Particularly effective on many different fruit trees including apple trees
- Compatible with some other fungicides. Check label instructions
- Not effective against some common fungal infections
- Restricted in Alaska, DC, Hawaii, and Florida
Runner-up Systemic Fungicide
Dow AgroSciences Eagle 20EW Fungicide
The Eagle 20EW Fungicide contains an ingredient called myclobutanil. Myclobutanil is used as a systemic fungicide. While most fungicides are solely preventative, systemic fungicides, such as this one, are curative as well. Furthermore, one of myclobutanil’s specialties is the apple tree.
This pick has overwhelmingly positive reviews and you can find this fungicide on Amazon.
- It’s a systemic fungicide
- Curative as well as preventative
- Highly potent
- Label for use on a wide variety of plants
- Effective on many fungal pathogens
- Considered hazardous
- Poses moderate environmental and ecological risks
Best Bulk Copper Fungicide
Monterey Liqui-Cop Liquid Copper Fungicide
Copper fungicides are a great preventative option during the dormant season. They are very popular, with so many different options out there, that it would be wrong to settle on just one best pick. Although copper is a common (and universally loved) fungicide, this copper fungicide is an option that stands out for its weather-resistant formulation. Sold in bulk containers of 1 or 2 gallons, it’s perfect for a backyard gardener with 2 or more trees.
- Available in gallon sizes
- Very specific temperature range for spraying
- Can be phytotoxic
Best Ready-to-Use Copper Fungicide
Bonide 775 Copper Fungicide
Copper fungicide is one of the most common types of fungicides. Mixtures and proportions of copper in the solution vary, but they’re all organic and will be effective against fungal infections including apple scab, powdery mildew, fire blight, rust, and black spot.
Read the label carefully because copper fungicide can be phytotoxic to apple trees.
This copper fungicide by Bonide has excellent reviews. Furthermore, you’re able to find this, or a very similar spray, at almost any hardware or gardening store. Online, you can find it for a low price on Amazon.
- Perhaps the most common and widely available type of fungicide
- Thousands of positive ratings
- Works great on apple trees
- Easy to use
- Can be detrimental if applied in high temperatures
- Vulnerable to being washed or blown away by weather
Pure PetraTools Neem Oil
Oil can serve as a non-chemical alternative to other fungicides. Neem oil, such as this one from Petra, comes from the seeds of the neem tree and can be used as a pesticide as well. The active ingredient in neem oil, azadirachtin, is safe and gentle on the environment while also being a formidable defense against infections such as rust, black spot, leaf spot disease, and mildews. Find this organic oil fungicide on Amazon.
- Lots of excellent reviews
- Works great as a pesticide and can have fungicide properties
- Can be harmful to your tree if applied in high temperatures
- More potent chemical alternatives are available
Bonide Sulfur Plant Fungicide
Sulfur has been used as a fungicide for thousands of years. It’s organic and effective at preventing illnesses such as rust, mildew, and black spot. Additionally, it’s safe for people and animals.
- One of the oldest kinds of fungicide in existence
- Works great as a pesticide as well as a fungicide
- OMRI listed product
- Easy to use
- Some plants can’t handle sulfur fungicides
- Not compatible with oil fungicides
- Can damage plants when applied in high temperatures
A Homemade Mixture
Most fungicides aren’t very expensive, but if you can’t get to the store, don’t want to wait for something to be shipped, or are just trying to save money, perhaps making your own fungicide from home is the right option for you. Plus, this homemade mixture is simple, made up of ingredients you likely already have at hand, and will be gentle on your apple tree and the environment.
Mix 4 teaspoons of baking soda (sodium bicarbonate) and 1 teaspoon of dish soap with one gallon of water. Spray this mixture directly onto the leaves of your tree.
- Easy on the environment
- Not toxic
- There are more potent fungicidal options available
How Fungi Can Affect a Tree
Symptoms vary between diseases, but it’s unlikely you’ll find any of them fun to look at. Some common effects on apple trees caused by fungal disease include:
- Lesions in the tree’s bark
- Withered leaves
- Ugly spots or holes in leaves
- Putrid fruit
- Long-term damage to the tree overall
There are many fungi that a tree could be affected by, and different plants have different vulnerabilities. The apple tree is no exception.
Types of Fungi to Which Apple Trees are Susceptible
The apple tree, or malus domestica, is susceptible to various fungal maladies. Infections such as apple scab, rot, rust, and mildew are quite unsightly, can decimate your tree’s yield, and can also seriously injure it. For more in-depth information, check out our post on the 10 Common Apple Tree Diseases for what you need to know to identify, treat, and prevent fungal diseases.
Do I Need the Strongest Available Fungicide?
It’s generally good to use the gentlest fungicide that’s effective for your apple tree. The most potent option isn’t always the right choice and can put undue strain on your tree and the environment. To kill a bug in your house, choose a flyswatter, not a nuke. Exaggeration aside, it’s usually best to try something more natural, especially if your focus is preventive.
When applying any fungicide, always follow label instructions carefully. Different fungicides will be used on different parts of your apple tree. It’s never a bad idea to put on a mask and long sleeves when mixing and applying your fungicide.
Additionally, to skip a step, try purchasing a version of your desired fungicide in a bottle that has a hose nozzle attachment. It’ll automatically create the mix in the desired proportions as you spray. Be sure to shake the bottle well.
Use What Works for You and Your Tree
You’re unlikely to go wrong with any of the fungicides on this list. They’re all great fungicides for your apple tree. The Dow AgroSciences Eagle Fungicide, in particular, is a great option for a potent, systemic fungicide. There are many great fungicidal options on the market and, if you can’t find one on this list, there are always others that are very similar. Searching for a fungicide by its active ingredient will lead you to lots of options.
Here at Minneopa Orchards, we’re passionate about apples and apple trees. That’s why our website has everything you need (and more) on the subject.
Excited for more apple content? Visit my apple trees page to learn more about apple planting, growing, harvesting, cooking, and more!