Cherry Leaf Spot: Fungal Disease | Treatment Guide
Cherry leaf spot (Blumeriella jaapii) is a fungal disease that primarily attacks cherries (sour and sweet cherries) and occasionally other Prunus species, such as ornamental cherries and plums. It thrives when the weather is cool and humid during spring and early summer. It is identified by small, round reddish-purple to brown spots on the leaves. Over time, these spots may drop out leaving small holes, while the leaves turn yellow and drop prematurely. On the underside of the leaves, small light to dark dots are sometimes visible where the fungus produces spores. The disease primarily overwinters in fallen leaves beneath the tree.
What is Cherry Leaf Spot?
Cherry Leaf Spot is a fungal condition with moderate severity that affects plants. Cherry leaf spot (Blumeriella jaapii) is a fungal disease that primarily attacks cherries (sour and sweet cherries) and occasionally other Prunus species, such as ornamental cherries and plums. It thrives when the weather is cool and humid during spring and early summer. It is identified by small, r...
Cherry Leaf Spot is a fungal disease with moderate severity. This condition is contagious and can spread between plants.
Unlike bacterial infections, Cherry Leaf Spot spreads slowly but is harder to eradicate. Without treatment, affected leaves won't recover. Without isolation, nearby plants can become infected within days.
🧪 Natural vs Chemical: Which Treatment Works for Cherry Leaf Spot?
🌱 Natural Solutions
- ✓ Rake up and remove infected leaves during the season and in autumn; dispose of them in household waste or hot compost if you are certain of high temperatures.
- ✓ Thin the canopy on a dry day to improve airflow and speed up drying, and disinfect tools between cuts.
- ✓ Water at the base using a watering can or soaker hose and avoid wetting the foliage.
- ✓ Place the tree in a sunny spot and avoid overcrowded plantings; apply 2–3 inches (5–8 cm) of mulch such as wood chips or leaf compost under the canopy to reduce splash dispersal.
- ✓ Use products approved in Sweden containing Bacillus species, such as B. subtilis/QST 713 or B. amyloliquefaciens, before and during risk periods according to the label.
💉 Chemical Solutions
- ✓ Only use products explicitly approved for leaf fungi on fruit trees in Sweden.
- ✓ Use preparations containing potassium bicarbonate if the label specifies use on cherry/Prunus.
- ✓ Treat from bud break until shortly after flowering and repeat during prolonged rainy periods according to the label instructions.
- ✓ Spray in dry, calm weather and use appropriate protective equipment.
🛡️ How to Prevent Cherry Leaf Spot?
TLDR: Prevent Cherry Leaf Spot with 7 essential care practices. Regular monitoring is key for early detection.
- ✓ Remove fallen leaves and mummified fruit every autumn and throughout the growing season.
- ✓ Prune annually to allow light and air into the canopy so that leaves dry quickly after rain.
- ✓ Avoid overhead sprinklers that wet the foliage; water at ground level instead.
- ✓ Avoid over-fertilizing with nitrogen, which produces soft, susceptible shoots.
- ✓ Plant in sunny locations with well-drained soil and maintain proper spacing between trees.
- ✓ Choose hardy and less susceptible varieties whenever possible.
- ✓ Begin preventative measures early in the spring, especially after mild, humid winters or if you have had previous outbreaks.
🔗Related Diseases
Rust
Rust fungi (Pucciniales) are fungal diseases that form rust-colored, usually orange to brown pustules with powdery spore dust on leaves, stems, or fruits. Typical symptoms include small spots that develop into cushions or rings; leaves turn yellow, curl, and drop prematurely. The fungi spread primarily in damp weather and dense foliage. Many ornamental and crop plants are affected, frequently including roses, mallows (hollyhocks), pears (pear rust), and currants. Some rust fungi require two host plants for their life cycle, such as pear and certain juniper species.
Cherry Witches' Broom
Taphrina wiesneri is a fungal disease affecting cherry trees (Prunus species, including sweet, sour, and ornamental varieties). The fungus overwinters in buds and bark, infecting young leaves and shoots during cool, wet spring weather. Infected leaves become thickened, puckered, and curled, often displaying reddish or yellow blotches and a fine whitish bloom on the surface. Severely affected leaves may drop prematurely. Small twigs can develop 'witches' brooms,' which are dense clusters of weak, distorted shoots.
Powdery Mildew
MediumPowdery mildew is a common fungal disease caused by various fungi species including Erysiphe, Podosphaera, Oïdium, and Leveillula. It affects over 10,000 plant species worldwide. The disease thrives in warm, dry climates with high humidity and appears as a distinctive white powdery coating on plant surfaces.
Root Rot
HighRoot rot is a serious fungal disease that affects the root system of plants, causing them to decay and die. It is primarily caused by overwatering, poor drainage, or soil-borne fungi such as Pythium, Phytophthora, Rhizoctonia, and Fusarium. The disease thrives in waterlogged conditions where roots are deprived of oxygen, making them susceptible to fungal infection.