I was interested in what the dark oak tree looked like so I was flying around in creative with swiftness but couldn't find any. I finally gave up and just got a sapling and bone meal from the menu. I put down the sapling and held down right click on it with bone meal for about 10 seconds, but nothing happened.
1. go into creative.
2. get dark oak sapling and bone meal.
3. place down sapling and right click with bone meal.