OAKLAND (CBS SF) – Palm trees are arriving on the approach to the Bay Bridge’s new eastern span this week.

The first four trees were planted Wednesday and four more will arrive Thursday, Bay Bridge spokesman Andrew Gordon said.

READ MORE: Santa Rosa Neighbors Blame City After Creek Overflows, Flooding Homes, Forcing Evacuations

The trees are being placed on the bridge approach on the Oakland side, between the eastbound and westbound lanes, just west of the toll plaza.

A total of 30 trees will eventually be added, Gordon said. The trees, which arrive full-grown and healthy, cost about $15,000 each to buy, ship and plant.

Caltrans put out a call earlier this year for private growers of Canary Island date palms who would be willing to sell the agency their trees. The trees ended up coming from all over the Bay Area and beyond.

That type of palm was chosen because it matches “the vertical symmetry on the bridge,” Gordon said.

READ MORE: Los Gatos Mayor Issues Warning To Residents To Stop Harassment At Council Meetings

It is the same type of palm that dots the Embarcadero in San Francisco. The Embarcadero trees have been plagued by disease, but Caltrans is working to ensure that doesn’t happen with the Bay Bridge palms.

To motorists, the trees will appear to either grow or shrink in height depending on the direction of travel, with the taller trees closer to the center of the bridge, Gordon said.

The tree planting is expected to be completed by next spring, he said. The planting activity is not expected to impact traffic, but motorists are reminded to keep their eyes on the road.

He said the trees can grow up to 50 feet tall, and require minimal care.

“They will need to be maintained just as you have to maintain the bridge,” he said.

The new $6.4 billion eastern span opened to traffic in September.

MORE NEWS: Lowell High School Alumni File Lawsuit To Reinstate Merit-Based Admissions

(Copyright 2013 by CBS San Francisco and Bay City News Service. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)