Pest Management

Bermuda buttercup infesting a bed of landscaped plants.

Pests in the Urban Landscape: Article

Spring is in the Air, and Oxalis is Everywhere

April 17, 2025

By Lindsey Hack

Bermuda buttercup (Oxalis pes-caprae), also called buttercup oxalis or sourgrass, might be a familiar sight in winter and spring, particularly to those who live in coastal regions or the Sacramento Valley. Some people enjoy seeing this plant’s cheerful yellow flowers pop up in their spring gardens, but for…

Thrips/TSWV status in Yolo & Colusa: Article

2025 First Report-- April 2

April 2, 2025

By Patricia A Lazicki

General situation, thrips population development Planting is in full swing. Temperatures and precipitation this spring are close to historic norms, and the thrips population predictions are very similar to those we saw last year. We’re currently at the peak of 1st-generation adults; they’ll be laying their…

Photo Forest and Lake by Katie Musial on Unsplash

ANR Contracts & Grants Updates: Article

2 RFPs - Vertebrate Pest Control Research and Forest Monitoring

March 27, 2025

By Kendra T Rose

Dear Colleagues,1) California Department of Food and Agriculture’s (CDFA) Integrated Pest Control Branch is now accepting applications for the Vertebrate Pest Control Research Program (VPCRP). This funding opportunity is designed to support innovative research and education projects aimed at…

Armillaria

UC Marin Master Gardeners: Document

Armillaria

Armillaria root rot, also known as Oak root fungus, is a disease of many different plants. There is no known effective cure. Root rot fungus disease of trees and woody plants. Affects palms, succulents, ferns and other herbaceous plants like begonia, daffodil, dahlia, and geranium. No…

Damping Off

UC Marin Master Gardeners: Document

Damping Off

Seedlings sometimes fail to sprout or die soon after. Seeds may rot before germinating, shoots may decay before they emerge, or stems of seedlings may be attacked near the soil line, causing young plants to collapse. These diseases are collectively called “damping off,” likely caused by a number of soil…

downy mildew

UC Marin Master Gardeners: Document

Downy Mildew

Downy mildews, including Peronospora and Plasmopara spp., are pathogenic water molds (oomycetes) that primarily damage foliage. Hosts include cane berries, roses, various herbaceous ornamentals, and many fruit, grain, and vegetable crops. Category Fungi Signs/Symptoms Downy mildew causes pale green to…

Brown, scorched-looking leaves are symptoms of fire blight in trees in the apple and pear family. Photo: Sebastian Stabinger

UC Marin Master Gardeners: Document

Fire Blight

Fire blight is a common and frequently destructive disease of pome fruit trees and related plants. The disease can destroy limbs and even entire shrubs or trees. Caused by the bacterium Erwinia amylovora. Pear (Pyrus species) and quince (Cydonia) are extremely susceptible. Apple, crabapple …

fusarium wilt

UC Marin Master Gardeners: Document

Fusarium Wilt

Fungus. Various host-specific forms of Fusarium oxysporum can kill infected plants. Hosts include asparagus, bean, cabbage, cantaloupe, pea, tomato, and watermelon. There are many varieties of host plants with resistance to Fusarium wilt.Like verticillium, causes leaf…

blight

UC Marin Master Gardeners: Document

Late Blight on Potatoes

Late blight of potato was responsible for the Irish potato famine of the late 1840s. Late blight is caused by the oomycete Phytophthora infestans. Oomycetes are fungus-like organisms also called water molds, but they are not true fungi. Category Fungi Signs/Symptoms Lesions appear as small dark green…

powdery mildew

UC Marin Master Gardeners: Document

Powdery Mildew

Powdery mildew is a common disease on many types of plants and is prevalent in many areas of California. Infection occurs when fungus contacts a suitable host and environmental conditions are favorable. Infections spread as spores produced in these white patches move by wind and splashing rain to other…