Phytophthora (fy-toff-thor-uh)

Symptom Guide: Camellia species

Phytophthora are microscopic organisms that cause disease in many plant species, including Camellia species.

You can learn more about Phytophthora and Sudden Oak Death at the links below.

Phytophthora (webpage)
Phytophthora Symptom ID Guide (webpage)
WSU Sudden Oak Death (webpage)
Sudden Oak Death Education Program (webpage)

Camellia species

Prized Garden Plants

Camellia species are beautiful ornamental shrubs and flowering trees that can be found throughout neighborhoods and gardens in the Pacific Northwest.

Diversity

There are more than 250 species of Camellia and many more cultivars and hybrids.

Regulated Species

All species, hybrids, and cultivars are regulated as proven hosts for Phytophthora ramorum.

Rows of small plants in pots outside a greenhouse

Phytophthora ramorum Symptoms

Leaf Lesions

On Camellia, brown lesions tend to form at the leaf tip and are irregular in shape when the plant is infected with P. ramorum. As with Rhododendron, lesions generally appear along the midrib and petiole. Occasionally lesions form at the edge of the leaf.

The lesions appear diffuse and water-soaked. No fruiting bodies (structures resembling pin-heads or molds) are visible.

young camellia plants in pots, many of which have brown lesions of various sizes — Lesions from *P. ramorum* infection on *Camellia sinensis* leaves

A leaf held in a hand. A small dead leaf is stuck to the outside. A small lesion on the right edge of the plant shows infection — *Camellia sp*. leaf with small lesion

Some of the leaves show lesions on the tips or along the midrib — Symptomatic Camellia plants in pots

Defoliation

Defoliation often occurs on lower leaves of infected Camellia plants. No canker or dieback symptoms have been observed on Camellia.

link to allow viewing detail — *P. ramorum* on Camellia (*C. japonica*) leaves. Lower leaves in photo also have some fungal symptoms with pinhead-like fruiting bodies.

Sunscald

Camellia foliage can be affected by sunscald. Lesions from sunscald have defined margins, are not water-soaked, and are not associated with the midrib. These lesions can become infected with opportunistic fungi such as Pestalotia and Pestalotiaopsis.

these lesions are lighter brown in color. One seems to be distorting the shape of its leaf. — Sunscald injury on Camellia leaves

More Resources

Learn more about Sudden Oak Death

More information, including links to youtube videos, about Sudden Oak Death . You can also find information for specific audiences (e.g. nursery professionals, garden managers, master gardeners, etc.) on our Sudden Oak Death Education Program webpage.

View more online symptom guides

There are many additional photos of symptoms on Camellia species in the other guides we have provided. Viewing multiple photos of symptoms on Camellia species may help you determine if Phytophthora ramorum is involved.

Management

Visit our webpage for Nursery Productions if you are looking for Best Management Practices for managing Phytophthora ramorum. These practices are also useful for managing other Phytophthora diseases, such as those that cause root disease, which can be more damaging on their hosts than P. ramorum.

Plant Disease Diagnostics

Guidelines for submitting a sample

Visit our Sample Submissions Guidelines webpage for information to help determine whether it will be helpful to submit a plant sample for professional diagnostics.