My dahlias are only about a foot tall but bushy and healthy. They get TONS of sun. I noticed today that Pennsgift is starting to form a bud so the others must be close behind. Will the plant continue to grow taller through the season or no? Should I pinch the buds or feed it something that will encourage top growth? (Time for more Jobe's tomato food spkes?)

I am just wondering in light of the fact that Pennsgift is supposed to make these big honkin flowers. In fact, three of the four are dinnerplates. I didn't have this issue two years ago when I grew them in another place. They all reached a nice 3-4 feet tall.