Alert from CDFA Plant Health and Prevention Services
The California Department of Food and Agriculture (CDFA) and the United States Department of Agriculture (USDA) have established a 94-square mile quarantine in portions of Riverside and San Bernardino counties following the detection of the citrus disease huanglongbing (HLB), or citrus greening. HLB is a deadly disease of citrus plants and closely related species, and can be transmitted from tree to tree by the Asian citrus psyllid.
On July 15, HLB was discovered in a grapefruit tree in the city of Riverside in a residential neighborhood near the intersection of Chicago...
Summer is a great time for outdoor activities like camping, hiking, and backpacking. During your adventures in natural areas, be on the lookout for poison oak. Poison oak, a well known plant for most people in California, is widespread in our state and can be encountered in open woodland areas, grassy hillsides, coniferous forests, and open chaparral.
Poison oak looks different depending on the time of year, and may be difficult to recognize. In spring, it has young leaves that are green or sometimes light red, along with small, white-green flowers. In late spring and summer, poison oak foliage is glossy green. As we head into late summer and early fall, the leaves will turn shades of orange and red with whitish-green,...
- Author: Stephanie Parreira
National Honey Bee Day is celebrated on the third Saturday of every August. This year it falls on Saturday the 19
This time of year, you may notice a white, powdery looking growth on fruit, vegetable plants or ornamental plants in your garden. What is it? It could be powdery mildew.
Powdery mildew is caused by several different fungi that may attack plant leaf surfaces, shoots, fruits, and flowers. There are several species of powdery mildew; all are spread by wind and thrive in shady areas when temperatures are between 60-80 °F. The fungi attack both new and old foliage, and can be a problem on certain plants. The disease usually occurs first on new leaves, before spreading to older parts of the plant. This is why over fertilizing worsens powdery mildew.
Ornamental Plants
Many woody and herbaceous...
Many areas in California have experienced a hot and dusty summer, perfect conditions that favor spider mites! These tiny arachnids are plant pests whose numbers can get very high during the warm months of June through September.
Spider mites damage plants by sucking cell contents from leaves. If you see plant leaves with light dots on them (stippling) that turn yellowish or reddish and drop off, and/or large amounts of fine webbing on leaves, twigs, and fruit, your plants might have spider mites.
Spider mites look like tiny, moving dots that will move around rapidly when disturbed. To correctly identify these pests, use a 10x hands lens to view...