Red Maple with Anthracnose? Rare but Treatable

Acer rubrum

Susceptibility: Low Severity: High Difficulty: Medium

Anthracnose on Red Maple: What to Know?

Anthracnose on Red Maple (Acer rubrum) is a fungal condition with high severity. Red Maple has low susceptibility to this disease. Anthracnose is a fungal disease caused by fungi in the genus Colletotrichum that affects many plants, including vegetables, fruits, and trees. The disease thrives in cool, wet conditions, causing dark...

Red Maple is a medium-care plant. Recovery from Anthracnose takes approximately 14 days with proper treatment.

Unlike most plants, Red Maple has natural resistance to Anthracnose. Best treated with preventive measures rather than reactive treatment. Unlike bacterial infections, Anthracnose on Red Maple can be managed with organic fungicides.

🔍 What Does Anthracnose Look Like on Red Maple?

• Small irregular yellow or brown spots on leaves
• Dark sunken lesions on leaves, stems, flowers and fruits
• Water-soaked lesions that darken as they age
• Pink gelatinous masses of spores in lesion centers during warm, moist weather
• Spots that expand and may cover entire leaves
• Defoliation in advanced stages

❓ What Causes Anthracnose on Red Maple?

→ Caused by fungi in the genus Colletotrichum
→ Cool wet weather promotes development
→ Optimum temperature between 75-85°F (24-29°C)
→ Foliage wet for extended periods of time
→ Fungi overwinter in seeds, soil and garden debris
→ Spores spread through water droplets

💊 How to Treat Anthracnose on Red Maple?

TLDR: Treat Anthracnose on Red Maple with quick treatment (~7 days) or organic (~14 days). Red Maple has low susceptibility to this disease.

⚡

Quick Fixes

Remove and discard all visibly infected parts

Apply commercial systemic fungicide (azoxystrobin or mancozeb)

Adjust irrigation to avoid wetting foliage

Second application of systemic fungicide

Assess treatment effectiveness

🌿

Organic Treatment

Remove all infected plant parts and discard in plastic bag

Apply organic liquid copper spray to all plant surfaces

Switch irrigation regime to drip, avoiding foliage wetting

Second application of copper fungicide or neem oil

Assess progress and remove any new lesions

Final organic fungicide application and ongoing monitoring

🛡️ How to Prevent Anthracnose on Red Maple?

TLDR: Prevent Anthracnose on Red Maple with 8 essential preventive care practices.

✓ Implement drip irrigation instead of overhead watering
✓ Give plants enough room to breathe and reduce humidity
✓ Remove infected plant material after harvest
✓ Practice crop rotation between hosts and non-hosts
✓ Choose resistant plant varieties when possible
✓ Use western grown seeds not exposed to the disease
✓ Avoid wetting foliage during watering
✓ Ensure good air circulation around plants

🌱 How to Care for Red Maple to Prevent Anthracnose?

💧 How to Water

Water deeply once a week for the first two years; established trees only need supplemental watering every 2–3 weeks during extended droughts.

☀️ Lighting

Plant in full sun for the best autumn color. Tolerates partial shade but may show less vivid fall foliage.

🪴 Ideal Soil

Prefers moist, well-drained loamy or acidic soils with a pH of 6.0–7.0. Tolerates clay, sand, and even occasionally waterlogged sites.

Frequently asked questions

Can Anthracnose kill my Red Maple?

Yes, without treatment, Anthracnose can be fatal to Red Maple. Early detection and treatment are key.

How long does Red Maple take to recover from Anthracnose?

With proper treatment, recovery takes approximately 14 days. Without treatment, it can take significantly longer.

Is Anthracnose contagious to other plants near Red Maple?

Yes, Anthracnose can spread to nearby plants. Isolate the affected Red Maple immediately.

See more: Red Maple → See more: Anthracnose →