Umbellularia californica
California bay (or CA bay laurel) is a large native tree most often found growing along streams or creeks, or in natural drainage areas. This tree is rarely planted for ornamental purposes, but is common in landscapes due to its rapid growth, seed spread, and ability to sprout from stumps.
- Culture
- Concerns
- Management
Culture for California Bay
CA bay grows best in deep, acidic, moist soil with high organic content. Supplemental irrigation is rarely needed due to the typical natural location of these trees, but the rare planted specimen might require some irrigation in summer. CA bay often grows long, overextended branches as it starts in shade and grows toward sun.
Concerns about California Bay
CA bay can reach large size and is very prone to root and basal decay, leading to whole tree failure. Bay laurels drive the ‘sudden oak death’ (SOD) epidemic as spores produced on bay leaves infect oaks, but do not kill the bay laurel. Bay laurels are also commonly infested with scale insects or the bay laurel aphid, which leads to honeydew and sooty mold on plants and surfaces below the canopy.
Management Practices for California Bay
Due to its role in sudden oak death, all bay laurels should be pruned to remove foliage from above or within oak canopies. This tree will sprout from stumps and complete removal often requires herbicide. Foliage should be inspected to determine SOD disease pressure on nearby oaks. Potassium phosphite treatments may reduce spore production in treated bay laurels. If honeydew or sooty mold is a problem, systemic treatment options are effective.
Photos related to California Bay
CA bay
Symptoms of Phytophthora ramorum, cause of ‘SOD’, on bay leaves
CA bay laurel aphid infestations on leaf bottom