My goal is always to get the young hummingbirds to figure out feeders before they migrate, as this almost guarantees their return in future years. As the population increases in my garden these young birds learn from the others about the feeders. Here's a young hummingbird that hasn't figured out the feeders yet, but has certainly differentiated between the flowers. Although the Zinnias and Calendula are very similar in appearance in this photo, this young bird dances from flower to flower bypassing the tasteless imitation.
I see flowers as training feeders. If you have enough of a great selection, the young hummingbirds will stick around long enough to figure out the feeders. Also, if they solve the feeders before they migrate south, they'll recognize every feeder along their path. Feeders can be so beneficial as they can gain an enormous amount of energy without expending a lot in such a short amount of time. In future years, they'll remember the location of every one that hung along their route to their summer home. This is why so many people have reported birds showing up at their windows when they first arrive in Spring. They remember what's great and where they hung.
But we can't forget the importance of flowers. They are so beneficial to attracting hummingbirds, especially the young. They naturally gravitate towards them until they solve and recognize the enormous value of the feeders.
Juvenile Ruby-throated hummingbird. N.E. of Edmonton, Alberta. 2015