This is a nighttime shot of a Witteman's Best dahlia from last year. I did a little experiment and didn't pinch any buds just to see if it would produce more but smaller flowers. There were many more flowers on this one than the ones I did pinch but the blooms were the same size( 5" ).
Morgan, I don't recall the name of the fertilizer but it was some type of organic from Lowes. I can't remember if this was two tubers or one tuber with a lot of spouts. They were kind of hard to stake with so many stems and thats why the ones in front appear to be leaning toward the camera. Here is a picture of one that I did pinch.
This is called a Witteman or Witteman's Best. I bought them most recently from Blooming Bulb and Holland Bulb Farm. HBF just ended a sale. These were five for a little less than nine dollars. The tubers were a little smaller than the ones from BB but they are growing nicely. They don't appear to be a very popular dahlia as I have only seen them for sell at a couple places.