When to Spray Copper Fungicide on Peach Trees

Are you a peach tree owner wondering about the best time to use copper fungicide? The dormant season is key. It's the perfect chance to protect your trees from diseases like peach leaf curl.

The dormant season is ideal because trees have no leaves. This means the fungicide can more easily get into the tree. It helps prevent many diseases. The best time to spray is around Thanksgiving, New Year's, and Valentine's Day.

So, what is peach leaf curl? Why does it cause problems, especially in places like California? Learning about this disease is important for peach tree care. Let's find out how to keep your peach trees healthy and productive.

Understanding Peach Leaf Curl

Peach leaf curl is a fungl disease caused by Taphrina deformans. It mainly affects leaves, turning them reddish, distorting them, and causing a puckered look. This disease may also harm flowers and fruits.

It thrives in cool, wet spring climates. This makes it common in those conditions. It's key to spot the signs early to avoid mistaking it for other problems like damage from aphids.

To avoid infection, the weather must be under 61°F. Spraying with a copper fungicide in the fall is often recommended. Products with liquid copper, such as Liqui-cop, can stick and work longer on plants. The amount you should use will differ depending on the product.

Using professional-grade stickers like Nu Film 17 can help better distribute fungicides. It's been seen that some diseases respond better to professional-grade over consumer-grade fungicides. If you're preventing certain diseases in spring, following up with lime-sulfur and oil is recommended.

Leaf discoloration
Reddish, distorted, and puckered leaves
Flower and fruit damage
Potential reduction in crop yield

Applying copper fungicides regularly can stop Peach Leaf Curl (PLC). However, the value of spraying the ground under trees with copper and lime sulfur is debatable. Protecting container-grown fruit trees from rain has proven effective in preventing PLC.

The Importance of Dormant Sprays

Keeping peach trees healthy is important. Dormant sprays are key in this effort. They include dormant oils and dormant copper fungicides.

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These sprays fight pests and diseases while the tree is asleep. They do this effectively during winter.

Dormant oils manage bugs that hide in winter. Copper sprays target diseases like peach leaf curl on trees. It's vital to apply these sprays at the right time, usually before holidays. This timing ensures better disease and pest control.

For the best disease control, experts advise using dormant sprays in March. Plan to apply fungicides like copper, ziram, lime sulfur, or chlorothalonil.

It's also important to remove old fruit. This helps prevent brown rot in fruit trees. For apples and pears, dormant copper sprays can fight fire blight and scab. Aim for 2 lb/A of copper when using these sprays.

Urea can help by breaking down old fruit in orchards. This lowers the chance of disease. Make sure to keep an eye on the weather and how the orchard is growing.

Use the NEWA website for weather info if you're in Pennsylvania. Following safety rules and product instructions is essential. This is when using chemical sprays in orchards.

By using dormant sprays correctly, peach growers can keep their trees healthy and safe from pests and diseases.

Choosing the Right Copper Fungicide

When picking a copper fungicide for peach trees, think about the different kinds and what they have in them. For example, Liqui-cop by Monterey has a special copper mix in it. Another type is copper soap, which is also called copper octanoate. These are both good for spraying on trees to fight diseases like peach leaf curl.

Some of these products also have helpful bacteria, like Bacillus amyloliquefaciens. They can help even more against bad fungi. Make sure to read the labels so you know the best way to use them safely.

If you're using a sprayer, it's suggested to use 100 gallons of water with your spray mix for every acre. After the flowers have bloomed, you only need a little bit of copper – just 0.5 oz per acre. Also, spraying copper and oxytetracycline every 7 days is best for stopping diseases. This method has been proven to work well.

Don't mix copper with things that are acidic. And, your spray water should not be too acidic either. A pH level of 6.0 or above in the water is important for keeping the plants safe. Avoid using copper mixes that can hurt the plants directly, too.

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Start using copper before you think a disease might come. It protects the plants. Choosing copper that has very small particles is a good idea. It sticks better to the plant leaves this way.

You can switch between spraying copper and oxytetracycline to make the copper less harmful to the plants. But, avoid spraying copper on cold, wet days. It could go too deep into the plants and hurt them.

When to Spray Copper Fungicide on Peach Trees

Applying copper fungicide on peach trees at the right time is very important. It's best to spray it when the tree is dormant, which is usually around holidays like Thanksgiving, New Year's, and Valentine's Day. This helps keep the trees healthy against diseases.

This timing works well because the trees are without leaves at that time. Without leaves, the fungicide can reach the whole tree easily. It works the best against diseases like peach leaf curl.

It's crucial to finish spraying before the buds start to open. After bud break if you spray, it could harm the tree. Always make sure you spray on time to protect the buds.

Spraying during the dormant season controls diseases on peach trees. This way, you can expect a good harvest later on.

Spray Timing
Peach Tree Stage
Recommended Action
Dormant Season (Late Fall/Early Winter)
Dormant, No Leaves
Apply copper fungicide to prevent peach leaf curl and other diseases
Bud Break (Early Spring)
Flower Buds Opening
Avoid spraying copper fungicide to prevent damage to flower buds
Growing Season (After Blossom)
Leaves and Fruit Development
Consider other pest and disease control measures as needed

Following a holiday-based spray schedule in the dormant season helps peach trees. It keeps diseases away and ensures a good harvest.

Application Tips and Best Practices

When you apply copper fungicide to peach trees, it's vital to do it right. Use around 100 gallons of spray per acre for good coverage. It's best not to spray when it's cold and the air is wet. This weather could make the fungicide absorb too fast and hurt the plants. This condition is called phytotoxicity.

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Always mix the copper fungicide well and make sure the water is slightly acidic, about 6.0 or more. And don't forget about safety. Wear the right gear, like long-sleeved shirts, long pants, closed-toe shoes, and chemical-resistant gloves, to protect yourself.

Know that copper fungicide stays active for a while. Start using it before plant diseases can actually hit. This method is effective against peach leaf curl. It's a fungus that makes peach leaves, flowers, and fruit look strange. They end up puckered, thick, and yellow.

Causal Organism
Peach Leaf Curl
Taphrina deformans
Puckered, thickened, and curled leaves that turn yellow
Brown Rot
Monilinia fructicola
Infected fruit turning into a mummy on the tree
Peach Scab
Venturia carpophila
Small dark spots on the fruit and twig infections on the current year's growth
Bacterial Spot
Xanthomonas arboricola pv. pruni
Small reddish purple spots on leaves and dark spots on fruit that become larger and crater-like

To protect peach trees from diseases, farmers should follow these tips. This will make sure their crops are healthy and plentiful.


Timing the application of copper fungicide on peach trees is key. Doing so helps in managing diseases like peach leaf curl effectively. The best time to spray is in the dormant season, often around holidays like Thanksgiving, New Year's, and Valentine's Day. Spraying at this time allows the copper to get deep into the trees. It provides protection before diseases can start.

It's vital to pick the right form of copper fungicide and know how to apply it. Understanding why dormant sprays matter is also important. This knowledge is critical for keeping peach orchards healthy and productive. A good disease management plan, with the right copper fungicide at the right time, will help growers. They can keep peach leaf curl under control and enjoy a great harvest every year.

Taking a proactive approach to peach leaf curl is essential. It includes focusing on spraying during the dormant season. This strategy can lead to healthier trees and better fruit. It also helps peach growers do well over time and keep their operations sustainable.

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