OAKLAND — Nestled in a canyon in an Oakland neighborhood lies a rare 7-acre oasis of green and multiple shades of rose, the Morcom Rose Garden, a 1930s-era formal garden with winding paths, climbing stairways and lovely fountains and pools. It is home to almost 5,000 rose bushes, and the fact that they all continue to bloom is partly due to a group of volunteers, appropriately named The Dedicated Deadheaders.