How to Treat Fruit Trees Organically: When to Spray for Disease

I don't know about you, but growing organic fruit is important to me, and so is getting a healthy harvest; luckily, we don't have to trade one for the other!

Once you identify the fly or bug damaging the blossom and boring holes in the fruit, you can learn how to apply and when to spray fruit trees with organic fungicide, insecticide, copper or dormant oil for a healthy harvest. Read on to learn how!

Image of fruit trees in an orchard full of blooms.

Note: This blog post has been updated to include two podcast episodes on fruit tree maintenance. Over the years, I’ve had multiple listeners asking about organic methods, so download each of these podcasts and listen to them at your leisure!

Fruit Trees for the Homestead

Whether you have a vast orchard or grow fruit trees in pots, it’s a smart addition to any homestead. I love plants that I just have to purchase once and receive bountiful harvests year after year in return.

Growing fruit trees has a learning curve, and knowing how to plant fruit trees and plant a fruit tree guild is important for a thriving orchard. Once your orchard is established, regular maintenance, such as pruning fruit trees and protecting them from disease and pests, should be next up.

BUT before you begin spraying your fruit trees, it’s critical to know what times of the year to spray fruit trees.

The Best Fruit Tree Spray

It’s important to note that I love using Neem Oil for organic pest control in the garden. This general-purpose wonder is great on fruit trees, vegetables and herbs. When using this or another organic spray, ensure it is 100% organic.

You want to be sure you’re using cold-pressed 100% Neem Oil because many products say that they are natural or that they use Neem Oil, but if you look at the ingredients, they have other synthetic ingredients and often other pesticides that are not considered organic.

This is the Neem Oil I use that is straight cold-pressed Neem oil only (note: this is a concentrate, so it will last you a long time and can also be used on fruit trees!) I also have this sprayer to use when applying the neem oil to plants and trees.

A woman smiling while pruning a fruit tree.

Fruit Tree Maintenance Tips

Knowing when to spray your fruit trees is essential to a healthy harvest. These easy preparation tips will get you on your way to achieving this task with a better end goal.

Tip #1 – Clean Up

It’s important to do a really good cleanup around your trees as a preventative measure. This is essential whether your trees show signs of infestation or disease. If the tree has any infection or disease, the leaves or fruit that dropped from the tree can harbor insects, larvae or disease spores.

You’ll want to clean it up and move it out so no further contamination takes place. Don’t put it in your compost pile since spores, like fungus, spread easily and are hard to kill. You don’t want it to infect your compost and other plant life. It’s best to burn the leaves and fruit or seal them in black garbage bags and dispose of them.

Tip #2 – Identify the Disease or Pest

Once you identify the pest or disease, know if it can survive freezing temperatures and learn the life cycle or when it lays its eggs, you can get busy treating the issues. Let's look closely at some common pests and diseases that can have a negative impact on fruit trees.

Aphids – These tiny pear-shaped insects suck the sap from the leaves they are hiding under, causing them to curl and distort. To control aphids, you can use organic insecticidal sprays specifically formulated to target these pests.
Codling Moth – This notorious pest infests apple and pear trees, causing damage to the fruit as larvae tunnel inside. Apply organic insecticidal sprays during the moth's flight period to prevent infestation.
Brown Rot – This fungal disease affects stone fruit trees, such as peaches, plums, and cherries. Organic fungicide sprays can help prevent and control brown rot, especially during periods of high humidity.
Apple Scab – This fungal disease causes dark, scaly lesions on apple tree leaves and fruit. Regular applications of organic fungicide sprays can effectively manage apple scab.
Fire Blight – This bacterial disease affects a variety of fruit trees, including apples, pears, and others in the Rosaceae family. Prune infected branches and apply organic antibacterial sprays to manage fire blight effectively.

Tip #3 -Treat the Total Tree

You can treat the tree once you clean up the leaves and fruit around the tree and identify what you are fighting against. When using an organic spray to fight pests or diseases, saturate the tree so you don’t leave the window of opportunity open for it to reinfect itself.

For example, the organic peach tree spray I'm using to treat peach leaf curl is this organic copper spray concentrate. I completely saturate the tree with this organic spray twice yearly.

I schedule a spray after ninety percent of the leaves drop in the Fall before our typically wet winters and again in the Spring right before budding. If you have drier winters, a thorough Fall application should be sufficient.

Tip #4 – Safety First

Even though we only use organic sprays, it’s important to use caution for yourself and other things like pets and farm animals. Spray in the morning when there is no chance of rain, and

when it isn’t windy because we don’t want to inhale it or get it in our eyes.

You’ll want to wear protective clothing such as long-sleeved shirts, pants, boots, gloves and safety glasses. We also want to be mindful of our pollinators and honey bees. If you are spraying where there are blossoms, it’s important to spray in the evening instead.

Tip #5 – Reapply Organic Fruit Tree Spray Schedule

Not only will you be applying spray in the Fall, but you’ll also need to reapply in the late Winter or early Spring, right when the leave buds come out. You’ll need to apply the spray to some of them when the tree blossoms and others post-blossom.

That is why it is essential to identify what you’re dealing with so you can mark on your calendar when you need to apply based on the life cycle of the disease or pest.

Check out my Family Garden Planner to keep you organized with personal fruit tree spray schedules and more, keeping track of all things concerning your specific gardening needs.

A woman standing in an orchard picking an apple from a tree.

Understanding Growth Stages

When selecting sprays, it is important to consider their compatibility with the stage of fruit development and any potential harm they may cause to beneficial insects.

Many organic fruit tree sprays are designed to be safe for pollinators and beneficial insects when used according to the instructions, protecting your fruit crops without harming the ecosystem.

A woman marking branches of a fruit tree with bright orange tape.

Dormant Season

During the dormant season, dormant sprays play a crucial role in maintaining the health and vigor of fruit trees. This dormant period typically occurs in winter or early spring when the temperature drops to around 40 degrees Fahrenheit or below.

One of the most common sprays is dormant oil, which effectively controls overwintering pests and diseases. This horticultural oil smothers and suffocates harmful insects and their eggs, preventing them from causing damage during the growing season.

The application of dormant sprays, such as Neem oil, during this period, can help break the pest and disease cycle, reducing the risk of infestations in the coming months. It is important to note that dormant sprays should be applied when the tree is completely dormant before any new growth appears.

A woman cutting an elderberry cutting from an elderberry tree.

Bud Break

As the weather warms up (typically when temperatures reach around 60 degrees Fahrenheit), buds begin to break. This is a crucial stage in fruit tree development.

During bud break, when the first signs of new growth emerge, fruit trees become susceptible to pests and diseases. The time buds start to open, revealing the delicate structures that will eventually become flowers and fruit. You can treat them with an organic general-purpose tree spray to safeguard health and productivity.

When choosing tree sprays for bud break, select an organic general-purpose product that is suitable for your specific fruit tree varieties. Most tree sprays contain a combination of insecticides, fungicides, and sometimes even miticides. This comprehensive approach allows broad-spectrum protection against common pests like aphids, caterpillars, and mites, as well as fungal diseases like powdery mildew and rust.

During bud break and throughout the growing season, keep an eye out for any abnormal signs like deformed leaves, discoloration, or pests. By promptly responding to any issues, you can take the necessary steps to protect your fruit trees and ensure a successful harvest.

Petal Fall

During petal fall, the flowers shed their petals, and the fruit begins to form. The petal fall phase is a critical time when the young fruit is susceptible to pests and diseases.

Consult with your local agricultural extension service or a horticulture expert to determine the most suitable sprays for your specific tree variety and location.

Remember that the timing and frequency of sprays during the petal fall stage may vary depending on factors such as the regional climate, tree variety, and pest prevalence. Monitoring your fruit trees regularly and adjusting the spray schedule as needed will help you maintain the health and vitality of your trees throughout the growing season.

A woman inspecting the apples on an apple tree.

Fruit Development

Fruit develops quickly, and as it grows and ripens, it becomes even more appealing to pests such as insects and diseases like fungal infections. These intruders can damage the fruit, resulting in reduced yield or even complete loss.

Organic fungicide sprays can prevent or control fungal diseases affecting the fruit, such as powdery mildew, rust, or fruit rot.

Similarly, insecticidal sprays can effectively control and eliminate insect pests that may attack the developing fruit. Insects like aphids, caterpillars, or fruit flies can cause significant damage, leading to deformities, discoloration, or premature fruit drop. You can keep these pests at bay and protect the fruit by applying organic insecticidal sprays at the right time.

A woman hanging an apple maggot trap in an apple tree.

Additional Pest Control Methods

In addition to spraying your fruit trees, there are additional methods you can adopt to protect your fruit trees from pests.

Beneficial Insects – These natural predators can be introduced to your orchard to prey on common pests, providing natural pest control. Ladybugs, Lacewings, and parasitic wasps are examples of beneficial insects that can help keep pest populations in check. Research the specific pests affecting your fruit trees and find the appropriate beneficial insects to combat them.
Traps – Sticky traps, pheromone traps, and fruit fly traps are effective ways to lure and capture pests. Some traps hang in the tree, attracting the flies and trapping them and their eggs. These yellow sticky traps seem like another great option and may be more user-friendly. By strategically placing these traps around your trees, you can monitor pest activity and reduce their populations. Regularly check the traps and dispose of captured pests to prevent further infestations.
Bagging – Another method to try is bagging the apple in its immaturity. This method is ideal if you have younger trees and not multiple trees. If they're too many, it would be a huge undertaking to bag the apples.
Deterring Predator Pressure – Regarding predator pressure, such as birds and deer, netting and fencing have been very effective on our homestead. It’s not always realistic to net or fence around your fruit trees, and in this case, I have found that having dogs also helps deter the birds and deer from competing for our harvest.