Sunflowers shading the walk

The house where I pick up my milk planted rows of sunflowers along their walkway and I've been watching them grow all summer long. They are very tall now, with huge heads and they have totally overwhelmed the walk.

My sunflowers are about three feet high, with heads one-eighth the size of these. I think mine don't get enough sun or water.

This family will be eating sunflowers all winter long!