Tree Diseases: A Closer Look at Peach Leaf Curl

Who doesn’t love fruit trees? Not only do you get beautiful flowering in the spring, but fresh fruit in summer just taste better when picked fresh.

Out West, peach trees are a landscape favorites, but they also come with a few quirks, and peach leaf curl is one of the most common (and most misunderstood) tree diseases out there.

The tricky part? By the time you notice the curled, discolored leaves, the infection has often already happened. That’s why knowing what to look for, and how to reduce risk early, can save a lot of time, stress, and tree decline later in the season.

In our ongoing series on tree diseases, we’re taking a closer look at peach leaf curl, breaking down this fungal disease in plain terms as well as the practical steps property you can take to manage it.

Quick Links:

• What Is Peach Leaf Curl?
• Peach Leaf Curl Symptoms: How to Recognize It
• What Causes Peach Leaf Curl?
• Managing Peach Leaf Curl in Trees
• Preventing Peach Leaf Curl
  

What Is Peach Leaf Curl?

Peach leaf curl is a common fungal tree disease affecting the new leaves of peach trees and, in some cases, nectarines. It largely interferes with normal growth and causes noticeable leaf distortion later in the season, hence the name.

One of the tricky things about peach leaf curl is that the infection typically happens before symptoms are visible. It often attacks late winter/early spring, during cool, wet periods when trees are dormant or just beginning to break bud. Unfortunately, by the time leaves show damage, the fungus has already been active for a while.

While peach leaf curl is rarely fatal to mature trees, like many tree diseases, repeated infections can weaken overall tree health, reduce canopy performance, and increase stress. This is especially true in urban areas and in some managed landscapes where trees already deal with other stressors like compacted soils, heat, and inconsistent watering.

Understanding what peach leaf curl is (and how it behaves seasonally) is the first step toward better prevention and smarter long-term care.

Peach Leaf Curl Symptoms: How to Recognize It

Some tree diseases are difficult to ID. That’s not Peach leaf curl. Once you know what you’re looking for, it’s one of the easier tree diseases to spot. As noted above, symptoms typically show up in early spring, shortly after leaves emerge. In many cases, the damage seems to appear suddenly, affecting new growth first.

Early leaves may appear distorted, but there are a few common symptoms to look for.

Common Peach Leaf Curl Symptoms

• Curling or twisting leaves- Leaves may look crumpled, warped, or tightly curled instead of flat and smooth.
  
  
• Thickened, swollen leaf tissue- Infected leaves often appear unusually thick or “puffy,” which is a key clue that this isn’t just drought stress or nutrient deficiency.
  
  
• Red, pink, or purplish discoloration- Many leaves develop vivid color changes, often starting as reddish patches and spreading across the leaf.
  
  
• Yellowing or browning as the disease progresses- Over time, infected leaves may turn yellow, then brown, and eventually dry out.
  
  
• Premature leaf drop- Severely affected leaves often fall off early, sometimes leaving branches partially bare by late spring.
  
  
• Weak or stunted new growth- If the tree loses too many leaves early, it may push out a second set of leaves, often at the cost of overall health.

In most cases, peach leaf curl affects the foliage more than the wood, but repeated infections typically weaken trees over time, especially if they’re not caught early.

What Causes Peach Leaf Curl?

Peach leaf curl is a fungal infection caused by the fungus Taphrina deformans, which targets peach (and sometimes nectarine) trees.

One of the most important things to understand is that the fungus doesn’t usually spread from leaf to leaf once symptoms appear. Instead, it survives between seasons by living on the tree’s surface, including buds, bark, and twig tissue, and then infects leaves as they begin to develop.

Because infection happens early, peach leaf curl is often a timing disease. The fungus is most successful when it reaches leaves right as they’re forming, before the tree has fully leafed out and before the leaf surface becomes more resistant.

In other words, the tree doesn’t “catch” peach leaf curl mid-summer. The groundwork is typically laid much earlier, and symptoms show up later as the leaves expand.

Understanding the cause and timing of infection makes mitigation and treatment strategies so effective for this particular tree disease.

Managing Peach Leaf Curl in Trees

Here’s where we’d normally talk about treating peach leaf curl, but once symptoms show up on the leaves, there’s no spray that will “fix” the curled foliage that season. At that point, treatment shifts to management and support for the tree, including reducing stress and planning ahead so the disease doesn’t return next year.

For property managers and city forestry teams, the good news is this: peach leaf curl is very manageable when you focus on the right steps at the right time.

What to Do When You See Symptoms of Peach Leaf Curl

• Don’t panic-prune the tree.
  Leaf curl can look dramatic, especially in severe cases, but heavy pruning during active stress can make things worse. Be mindful of the special needs of fruit tree pruning as well!
  
  
• Remove heavily infected leaves if practical (and if it won’t harm the tree).
  Light cleanup can help, but most of the time the tree will drop damaged leaves on its own.
  
  
• Keep the tree watered consistently.
  Trees with peach leaf curl often need extra support because they may lose leaves early and have to push new growth. Watering, including winter watering, ensures they have the resources to survive.
  
  
• Avoid high-nitrogen fertilizer.
  If I’m trying to support the tree, isn’t fertilizer good? Not quite. High-nitrogen fertilizer can push a tree into fast, soft growth at exactly the wrong time. When a tree is fighting disease or has lost a bunch of leaves, it’s already running low on energy. If you add a lot of nitrogen, the tree responds by trying to produce a surge of new leaves and shoots. That new growth:
  
  
• Costs a lot of stored energy (carbs the tree needs for recovery)
  
  
• Is often more tender and vulnerable to pests and additional disease pressure
  
  
• Can create more canopy density, which can increase moisture retention and reduce airflow
  
  
• May lead to weak, “lush” growth that doesn’t harden off well, especially if weather shifts

Thankfully, unlike other tree diseases, there is a way to prevent peach leaf curl.

Preventing Peach Leaf Curl

When it comes to peach leaf curl, prevention is everything. Once the leaves are curled and discolored, the fungus has already done its work for the season. The best way to beat it? Stop the infection before buds open. For that reason, prevention is largely focused on dormant-season care.

Copper Spraying: The Most Effective Prevention Tool

For most properties and municipal landscapes, the most reliable preventive measure is a dormant spray with a copper-based fungicide (often labeled as copper soap, copper hydroxide, or copper fungicide).

Copper works by creating a protective coating on the tree’s surface that helps kill fungal spores before they infect emerging leaves. Remember, it’s preventive, not curative; it must be applied before leaf tissue is exposed.

When to Spray (Timing Matters More Than Anything)

Copper is typically applied twice yearly:

• After leaf drop in fall
  
  
• In late winter to early spring, just before bud swell and before buds open

Key Application Notes (Especially for Property Managers)

• Coverage matters: the spray must coat buds, twigs, and branch surfaces, not just the trunk.
  
  
• Apply during dry conditions when temperatures are safely above freezing.
  
  
• Timing is critical. Copper can cause plant injury if applied too late (once green tissue is present). Apply twice a year: after the leaf drop in the fall, and before budding begins in the spring.
  
  
• Always follow label instructions and local extension guidance for your region or call an arborist for help.

Support Prevention with Good Tree Health Practices

While copper spray is highly effective when applied correctly, it works best when paired with a few basic prevention steps:

• Keep trees consistently watered (without overwatering). This may include winter watering to ensure trees are strong as they enter spring.
  
  
• Avoid excessive nitrogen fertilization. Again, this may push too much growth, too fast.
  
  
• Maintain good airflow through thoughtful tree pruning. This helps prevent wet conditions that can allow a fungal infection to thrive.
  
  
• Clean up leaf litter and debris around the base of the tree

For property managers and city crews, peach leaf curl is one of the most manageable tree diseases when a prevention plan is in place before spring.

As always, if you’re struggling to identify a tree issue, call in a certified arborist. They can help you identify what you’re dealing with, with certainty, and ensure your response fits the concern you’re facing.

If you’re unfamiliar with tree treatments and preventative spraying, it may be best to call in a company that offers tree services in your area. With peach leaf curl, it’s imperative that the entire tree be covered and having help can ensure your preventative efforts are effective.

If you’re looking for tree services in Utah, Colorado, or Oregon, SuperTrees has you covered. In addition to being a wholesale tree nursery leader in the West, we also provide comprehensive tree services including spraying, pruning, watering, and more. Reach out to our team today for more information!