I just had a Palm Warbler feeding in weedy areas between garden plots at the GHGP here:
34.4204816, -119.8592302
The bird was confiding and let me digiscope a video from ~15 ft away. It's pretty easy to pick out with the constant tail wagging.
Keep in mind that this is an active community garden for UCSB students and staff so if you come by please be respectful of others' space and plants. In particular please don't step in garden beds.