New disease warning!
Imagine a world without oregano. Or celery. Or sage. Or chrysanthemums. It could happen.
There is a new plant disease and its name is Phytophthora tentaculata. [Wait! Come back!]
Just because this disease is tricky to pronounce (Fie-TOF-ther-uh), doesn’t mean you can ignore it. Its name is from the Greek phytón (plant) and phthorá (destruction), so the name phytophthora means “the plant-destroyer”. (The tentaculata part of the name refers to the tentacle shape of these particular pathogens.)
First noted in Germany in 1993, Phytophthora tentaculata hitched a ride on contaminated nursery stock and made its way to Central California and Monterey County, our Bay Area neighbors, in 2012. It is spreading rapidly and is deadly to many of your garden and landscape plants.
According to the Retail Nursery and Garden Center IPM News, Phytophthora tentaculata poses long term potential environmental and economic threat to many California native and non-native plants, as this pathogen can stay in the soil for many years and there is currently no known treatment.
What is Phytophthora tentaculata?
Phytophthora tentaculata is a member of the water mold family. In the world of scientific classification, water molds fall between fungi and algae. These pathogens attack stems and roots and frequently kill its host plant. There are several types of phytophthora, including those that cause potato blight, crown rot, and sudden oak death. You cannot see these organisms with the naked eye, but it is important that you keep a look out for the symptoms and know which plants are currently considered susceptible.
Many California native plants are highly susceptible to Phytophthora tentaculata. The most recent list includes:
Non-native plants that are at risk include:
Symptoms of Phytophthora tentaculata
Preventing Phytophthora tentaculata infestation
Contaminated nursery stock is the most likely way this pest will reach your garden or landscape and water management is the best way to prevent infestation. Phytophthora tentaculata are soil borne, which means they spread by sticking to plants, tools, containers, and shoes. Phytophthora tentaculata spores can also travel through the movement of water. This means that spraying an infested plant can transfer the water molds to nearby plants. Since symptoms do not appear right away, it is in your garden’s best interest to stay away from unhealthy-looking plants until you know for sure what is going on.
If Phytophthora tentaculata appears in your garden or landscape, contact your local Cooperative Extension Office right away. They may have helpful advice that will protect your plants and they need to know how far this disease is spreading.
I hope this information inspires you to grow more of your own food. You can ask your garden questions on my Home page.