Growing beautiful, healthy stone fruit in your backyard is one of life’s great pleasures. That is, until one of the many stone fruit diseases strikes.

We know how devastating it feels to watch your promising crop of peaches, nectarines, apricots, plums, or cherries succumb to fungal infections or other ailments. Trust us, we’ve been there!

There is good news, though, as most stone fruit diseases are largely preventable when you take the right action at the right time. Let’s dive into the most common stone fruit diseases and, more importantly, how to keep your trees healthy and productive.

The top stone fruit diseases every grower should know about

Brown rot: the most devastating stone fruit disease

Q: What exactly is brown rot, and how do I recognise it? 

Brown rot is arguably the most serious disease affecting stone fruits. The disease can spread horrifyingly quickly, especially during rainy weather, moving from one piece of fruit to another and even from tree to tree.

Q: What does brown rot look like? 

This disease does exactly what it says on the packet: it causes fruit to rot, and the rotten spots go brown! It starts as individual spots, which quickly spreads over the whole fruit. Tiny white fungal bodies may be visible in advanced cases. 

Q: Which stone fruits get brown rot? 

Apricots, peaches, nectarines, cherries, and plums can all be affected by brown rot. No stone fruit is completely immune, though some varieties are more resistant than others.

Q: When is brown rot most likely to strike?

It particularly loves weather that is both wet and warm. If you’ve had a rainy fruit season in your part of the world, you’re at a much higher risk of a brown rot outbreak. In Australia, the Bureau of Meteorology even issues brown rot warnings!

Read on

• Preventing brown rot on stone fruit 
• Treating brown rot on stone fruit 

Blossom blight

Q: What does blossom blight look like? 

Stone fruit flowers with blossom blight will shrivel up, and the petals will go brown and clump together. Rather than falling cleanly like healthy flowers, infected blossoms hang on the tree and turn brown.

Q: What’s the connection between blossom blight and brown rot? 

Here’s something that surprises many gardeners: Brown rot is caused by the same fungus as blossom blight. If you get blossom blight in the tree in spring, there’s a good chance you’ll get brown rot later in the season.

Q: Why is blossom blight so serious? 

The fungus causes the flowers to die. Apricot trees only flower once each season. If a flower dies, it can’t turn into fruit, which means you lose the crop. The infection can then move into twigs and small laterals, causing dieback.

Read on

• Identifying blossom blight on stone fruit 
• Preventing fungal disease on stone fruit
• Treating fungal diseases organically 

Peach leaf curl 

Q: Why are my peach and nectarine leaves curling? 

Peach leaf curl is a very common disease, and in fact, ONLY infects peaches and nectarines. If you’re seeing curly leaves on other stone fruits like plums or cherries, the cause is likely something else (often aphids).

Q: What does peach leaf curl look like? 

• Leaves become thick, puckered, and distorted
• Affected leaves often turn reddish or purplish, then turn black as the disease advances
• Severely infected leaves may fall prematurely
• New growth appears normal once the disease runs its course

Q: Does peach leaf curl cause permanent damage? 

The good news is that Leaf curl disease shows up in spring, does the damage, and then disappears (until next spring). If your trees were infected last spring, they should have completely recovered by mid to late summer.

Read on

• Identifying and treating peach leaf curl 

Gummosis and cankers – when trees “bleed” sap

Q: Why is my stone fruit tree oozing sap?

A canker is often just a blob of gum or resin (which is actually the tree’s sap) on the bark. This condition, called gummosis, can have several causes in stone fruits.

What causes the stone fruit disease of gummosis? 

Generally, it will be either physical damage from weather, animals, or tools, fungal diseases like Phytophthora or bacterial canker, or stress from poor growing conditions.

When should you be concerned about cankers?

While some gumming is normal, excessive sap production combined with dieback could indicate a fungal disease called Phytophthora, which is sometimes called root rot disease. Read this article on how to identify whether your cankers are caused by Phytophthora 

Learn more about preventing and treating cankers

• Animal damage 
• Treating Phytophthora (the fungal disease that causes gummosis) 

Shot hole disease: When leaves look bullet-riddled

Q: What causes those round holes in my stone fruit leaves? 

Shot hole is another common stone fruit disease. It’s a fungal disease that affects most stone fruits, but in particular apricots. You can identify shot hole by the leaves, which will be riddled with small, round holes. It looks almost as if they’ve been shot with tiny pellets.

Should you be worried about shot hole disease in your stone fruit trees?

Shot hole begins as reddish-brown spots that dry out and fall away, causing holes. It’s mainly cosmetic and doesn’t significantly impact tree health or fruit quality.

How to treat shot hole disease

Shot hole happens when the fungus is spread, usually during wet periods. We recommend preventative treatment of a copper spray, which is part of the organic growers ‘arsenal’, to be the best way to prevent the disease.

However, if you do need to treat it, then prune out and make sure you burn the infected wood to avoid spreading it any further.

Prevention is your best defence against stone fruit diseases

We are firm believers in preventing stone fruit disease. In our orchard, we only use organic principles, which have served us well over the years. The following is our recommended approach to healthy stone fruit. 

1. Choose the right location Plant your stone fruits in areas with good air circulation and morning sun to help leaves dry quickly after rain or dew.
2. Select disease-resistant varieties While no variety is completely immune, some show better resistance to common diseases. Research varieties suited to your climate.
3. Maintain excellent garden hygiene Removing infected fruit, cutting out infected wood, and preventing crawling insects from biting the fruit will all help. This includes:

• Picking up all fallen fruit immediately
• Removing any infected fruit from the tree (but just because an insect is present doesn’t mean it’s causing harm, so be sure to identify good or bad insects first!) 
• Pruning out diseased wood during the dormant season.

4. Proper spacing and pruning If the fruit is not touching each other as it’s growing, it’s much harder for disease to spread. Thin fruit appropriately and maintain an open tree structure.
5. Strategic spraying Preventive spraying is also key, especially in wet years. Use organic fungicides like sulphur or copper (sparingly) during high-risk periods.

Timing your prevention strategy

Q: When should I start thinking about disease prevention?

Stone fruit disease prevention is a year-round commitment. Here’s how we approach our stone fruit care.

❄️ Winter (Dormant Season):

• Prune to improve air circulation
• Clean up any remaining fallen fruit or leaves

🪷 Early Spring (when the flower buds swell):

• Apply preventive fungicide copper-based sprays sparingly but at the right time
• Keep an eye out for any aphid activity and move to manage them

🍃 Spring (when blossoms emerge through to petals falling and leaves start to emerge):

• Continue disease monitoring
• Begin fruit thinning programs 
• Watch for blossom blight symptoms

🍑 Summer (when fruit is developing):

• Monitor for brown rot, especially during wet weather
• Maintain preventive spray schedule 
• Always practice garden hygiene by picking up any diseased fruit 

Autumn (when leaves are falling): 

• Spray copper at 75% leaf fall if fungal disease has proven difficult to control using other methods

Treating stone fruit disease

Q: How can I treat stone fruit diseases? 

Some fungal diseases are untreatable once you have them. Leaf curl in peaches and nectarines is a classic example. But others, like brown rot, are definitely worth treating to stop them from spreading and getting worse.

Brown rot treatment

Q: My fruit has brown rot. What should I do?

Treating brown rot is as simple as picking any fruit that shows symptoms. Also, pick up any fruit that has fallen to the ground. Make sure you dispose of it well away from the tree. Of course, it’s best to prevent the disease from starting in the first place if possible (read more on organic prevention and treatment of diseases) 

You can:

• Compost infected fruit (if your composting system gets hot enough to kill the spores)
• Feed to animals (if it’s not too far gone, the infected portions won’t hurt most animals)
• Use for cooking after cutting away diseased parts.

Q: Should I remove all the fruit if I see brown rot?

There’s NO need to pull all the fruit off. That just needlessly wastes fruit that may still be able to be saved. Instead, focus on removing obviously infected fruit and maintaining a protective spray program.

Using organic fungicides

Q: What’s the best organic spray for stone fruit diseases?

The main solution is to use a “cover spray” of an allowable organic fungicide. We prefer sulphur, because it’s one of the least harmful, it’s relatively easy to use, and (if you use the right type) it can be very effective.

Safe organic options:

• Sulphur-based sprays (least harmful option)
• Copper-based sprays (use sparingly due to soil impact)

Read more about our organic approach to spraying trees 

Special considerations for different stone fruits

Apricots and stone fruit disease

Q: Why are apricots so difficult to grow successfully? 

That’s mainly because they get so many diseases. On top of that, they’re vulnerable to frost, and they can generally just be very fussy to grow. Apricots are particularly susceptible to:

• Blossom blight and brown rot 
• Shot hole disease
• Freckle (a cosmetic spotting disease)
• Frost damage due to early flowering.

Peaches and nectarines: Managing leaf curl 

Q: How can I prevent peach leaf curl?

Prevention is key since leaf curl is a nasty fungal disease that affects peach and nectarine trees, and there’s no cure once it appears. Apply copper-based fungicides in spring, just as the buds begin to swell.

Plums and cherries: Different challenges

While plums and cherries can get brown rot and other stone fruit diseases, they often face different issues:

• Plums are particularly susceptible to aphid infestations
• Cherries may experience bacterial canker
• Both can suffer from silver leaf disease in some regions.

Creating a disease-free stone fruit garden

Building tree immunity through soil health 

The secret to disease-resistant stone fruits starts underground. Healthy, well-drained soil with lots of organic matter is the perfect breeding ground for healthy soil fungi. Once established, they will out-compete Phytophthora and other disease-causing organisms.

Key soil improvements:

• Add quality compost annually
• Ensure good drainage
• Maintain appropriate soil pH (6.0-7.0 for most stone fruits)
• Encourage beneficial soil microorganisms (take a look at our article on soil health)

Encouraging beneficial insects 

Learning to appreciate insects was an important part of our journey to a truly organic mindset. Not all insects are enemies—many help control pest populations that can damage fruit and create entry points for diseases.

Learn more 

The importance of monitoring

Regular monitoring is crucial for catching diseases early. The trick is to identify the disease as soon as possible and then learn what to do about it.

Weekly monitoring checklist:

• Check for fallen fruit and remove it immediately
• Inspect fruit for early brown rot symptoms
• Look for unusual leaf curling or discolouration
• Monitor for insect damage that could lead to infections
• Assess overall tree health and vigour

Read more about this particular issue 

Grow Great Fruit Program

Are you worrying about the leaves on your fruit trees? Let’s get to the bottom of that—and set you up for your best fruit-growing year yet.

In the Grow Great Fruit program, we help you tackle leaf problems and we give you skills to grow healthier trees and bigger harvests across your whole orchard.

Each week you get a checklist of seasonal jobs to prevent issues before they start. There are step-by-step videos and guides on pruning, pest and disease prevention, and every other fruit growing topic.

Need answers? The Members Forum is full of answered questions from other growers who’ve been in your shoes. And Premium members get personal answers to questions from us for quick, expert support.

Let’s get your fruit trees thriving—this season and beyond.