Plant Diseases

Figuring out what's wrong with your plant takes a little detective work. Plants can look unhealthy for a number of reasons, including diseases, pest insects, or even environmental conditions like sunburn, too much water, not enough water, wind damage, and other issues.

Strong winds from the latest winter storm have downed trees and branches throughout Northern California and may have also damaged plants in your garden and landscape. Further damage from wind or hail can be reduced with proper cultural care.

Sooty mold is a black fungal growth that looks like a layer of soot covering the leaves of a plant or a sidewalk. The aptly named disease is common in gardens and landscapes, appearing wherever a large infestation of plant-sucking insects are found.

Your customers want their lawns to be beautiful and functional (Figure 1) but dead patches or other problems sometimes occur. Figuring out the cause of turfgrass damage can be a challenge since many plant pathogens affect grasses as well as numerous abiotic (non-living) disorders.

Sudden oak death is a disease of oak trees that is caused by an invasive plant pathogen Phytophthora ramorum. The disease has been found infecting trees in coastal California counties from Monterey to Humboldt and can be spread by moving infested soil and plant material. In California, P.

Anthracnose is a group of fungal diseases that infect many trees and shrubs, causing dark lesions on leaves and cankers on twigs and stems. In some areas of California, vegetables and turfgrass can also be infected with anthracnose. Symptoms of anthracnose vary by plant host and weather conditions.

As you practice social distancing during COVID-19, you may find yourself spending more time in the garden. As we move into nice weather, we are sharing a few gardening tips for pest management. Check for signs of powdery mildew on fruit trees, landscape ornamentals, and vegetables.

Roses in the garden can be infected with a variety of bacteria, fungi, and viruses, leading to diseases like powdery mildew and rust. Roses may also be damaged by nutrient deficiencies and other environmental problems.

Armillaria root rot is a severe fungal disease that affects trees, woody plants, and some herbaceous plants including palms and succulents.

The California Department of Food and Agriculture has declared a quarantine following the detection of Huanglongbing (HLB) in multiple residential citrus trees in Corona (Riverside County). This is the first time HLB has been detected in Corona.