HOW TO PLANT A TREE
The easiest (and most fun) way to plant a tree is to do it through Friends of the Urban Forest. They'll make it easy, you'll get to meet your neighbors, and you'll save a lot of money.
But if you can't wait until the next FUF planting in your neighborhood, you can try planting a tree by yourself. First, you'll need a tree. Most of the nurseries in the Bay Area with the biggest selection of trees are wholesale nurseries - they won't sell directly to individuals. (You can get into those nurseries if you work with a professional arborist - more on that below.) There are a couple of nurseries that will sell to the retail public.
Retail Nurseries
Wegman's Nursery, Woodside Road @ Highway 101 (lots of 5 gallon trees, a smaller assortment of 15 gallon trees, and 24 gallon trees available by ordering them); (650) 368-5908.
Berkely Hort Nurseries at 1310 McGee Ave, Berkeley; (510) 526-4704. Mostly 5 gallon trees.
Wholesale Nurseries
(These will sell to gardening professionals only)
Boething Treeland Farms at 2923 Alpine Road in Portola Valley; (650) 851-4770
Pacific Nursery at 2499 Hillside Boulevard in Colma (wholesale only); (650) 755-2330