Look for the trailhead on the east side of the road shortly south of the Sunflower trailhead. Head up and wind through large boulders, working your way up to the top of the canyon. There are some really nice views along the way and from the top.
At the top, there's a fork in the trail. Go right at this fork to continue on Rock Garden Trail that ends shortly at Rylander Fortress Cliff Trail, a dirt road. Going left at the fork takes one to a second fork. At this second fork, going left dead ends at a great overlook, great place for snacking and lunch. Going right at the second fork (after going left at the first fork) puts one on Rock Garden/Fortress Cliff Connector, a short, narrow singlepath trail that also leads to Rylander Fortress Cliff Trail.
Drop back down from whence you came. The combination of loose trail, tight switchbacks and more climbing than you may expect, could make the way back challenging.