Caltrans selected adult Canary Island date palms for the San Francisco-Oakland Bay Bridge to match the bridge's "vertical symmetry."

Adult Canary Island date palms are being planted at the entrance to the San Francisco-Oakland Bay Bridge's eastern span, a $900,000 landscaping effort that is the final touch for the $6.4 billion San Francisco Bay Bridge, whose new east span opened to traffic September 2, 2013 (baybridgeinfo.org).

Caltrans, which will plant a total of 30 date palms, estimates the cost of purchasing, planting and maintaining each palm for three years is about $15,000.

The date palms for the bridge were selected from a pool of about 150 trees, which were tested for disease and bugs. This careful selection work was important, given the health of the 222 date palms that line San Francisco's Embarcadero. A contagious fungus, fusarium wilt, is affecting some of those threes. Local media reports say four of the date palms have already been replaced on the Embarcadero, but 26 palms are infected, and another 34 have browning fronds, an indication the fungus is interfering with the trees' ability to take up water.