Anthracnose on Plants: Signs, Causes & Treatment
Learn how to recognize anthracnose symptoms, understand conditions that encourage infection, and use practical steps to manage and prevent this group of plant diseases.
Symptoms vary by plant and by the fungus involved. Leaf spots may be tan, brown or dark, while stems and twigs can develop lesions or dieback. Accurate diagnosis depends on the host plant and symptom pattern.
What Is Anthracnose?
Anthracnose is a general name used for diseases caused by several fungi. Different anthracnose diseases affect different plants, so the exact pathogen and symptoms are not identical in every case.
Extension resources document anthracnose on plants including ash, dogwood, oak, hosta and brambles. Some forms primarily affect leaves, while others can affect twigs, stems, flowers or fruit.
Signs of Anthracnose
Common symptoms can include:
What Conditions Encourage Anthracnose?
- Weather conditions favorable to the particular anthracnose disease
- Wet periods and leaf wetness for many anthracnose diseases
- New, tender plant growth during susceptible stages
- Infected leaves, twigs or plant debris that can provide inoculum
- Poor sanitation around plants with recurring disease
The exact environmental trigger varies. For example, Penn State notes that some shade-tree anthracnose is strongly favored by cool conditions around bud break, while wet weather can also support disease development.
How to Identify Anthracnose
Start by looking at the plant species, the location of the symptoms and the pattern of damage. Some anthracnose lesions have darker margins, while others form irregular tan blotches or sunken lesions on stems.
| What you see | What it may suggest |
|---|---|
| Tan or brown leaf blotches with darker borders | Anthracnose can be one possibility, especially on a known susceptible host. |
| Spots concentrated along leaf veins or margins | Can occur with some anthracnose diseases. |
| Sunken lesions on young canes or stems | Some anthracnose diseases produce distinctive stem or cane lesions. |
| White powdery growth | More consistent with powdery mildew than anthracnose. |
| Orange or rust-colored pustules | More consistent with plant rust. |
How to Manage Anthracnose
1. Remove infected plant material
Where practical, remove and dispose of infected leaves, twigs or canes. Penn State recommends pruning and destroying infected material for several anthracnose diseases.
2. Improve sanitation
Remove fallen leaves and other infected debris around susceptible plants when recommended for that disease. Sanitation can reduce sources of fungal spores for the next infection cycle.
3. Keep foliage as dry as practical
For susceptible plants, avoid unnecessary overhead watering and use irrigation methods that reduce prolonged leaf wetness when practical.
4. Improve airflow
Reduce overcrowding and remove unnecessary dense growth where appropriate so foliage can dry more quickly.
5. Consider fungicides only when appropriate
For some high-value or repeatedly affected plants, fungicides may be used to protect new growth. The timing and permitted products depend on the plant and the specific disease, so follow the product label and local extension guidance rather than using a universal schedule.
How to Prevent Anthracnose
- Choose healthy, disease-free planting material.
- Monitor susceptible plants regularly, especially during vulnerable growth periods.
- Remove infected leaves, twigs and fallen debris where appropriate.
- Maintain good air movement around foliage.
- Avoid unnecessary leaf wetness.
- Reduce plant stress with appropriate watering and growing conditions.
- Use resistant or less-susceptible varieties when reliable resistance information is available.
What Plants Can Get Anthracnose?
Anthracnose occurs on many different plant groups. Penn State resources document it on plants such as ash, dogwood, oak, hosta and brambles. The symptoms and disease-causing fungi differ among hosts, so plant-specific guidance is useful.
Not Sure What’s Affecting Your Plant?
Start with the symptoms you’re seeing and explore possible plant problems, pests, diseases and practical solutions with PlantySolve.
Diagnose My PlantFrequently Asked Questions
What does anthracnose look like on plants?
It varies by plant. Common symptoms include tan, brown or dark leaf spots, larger blotches, dead leaf margins or veins, and sometimes lesions on twigs, stems or canes.
Is anthracnose a fungal disease?
Yes. Anthracnose is a general term for several plant diseases caused by fungi, and the exact fungus depends on the host and disease.
How do I manage anthracnose?
Management can include sanitation, removing infected tissue, improving airflow and reducing unnecessary leaf wetness. Some diseases may also require appropriately labeled fungicides to protect new growth.
Can anthracnose spread to other plants?
Some anthracnose fungi produce spores that can spread to nearby susceptible tissue through wind, rain or splashing water. The risk depends on the specific disease.