Not sure but in case you did not already know, you can get Little Limes so that you'd get a Limelight that would be more the size you want.

thanks, I found that out after I planted the large ones ;-)

Before I go find a different spot for my pinky winkys does anybody know if I can keep them around 4 feet tall max. How long does it take for the limelights and pinky winkys to reach 6-8 feet?

I asked a garden center how long it takes for Quick Fires to reach maturity, which I think would be about the same. I was told that a 2 gallon would take 2-3 years.

There are so many variables that impact time to mature, soil type being one of the major factors.

In a sandy soil with consistent irrigation H. paniculata could easily get 6' in 2-3 years from a 2 gallon pot. In a clay based soil that isn't irrigated regularly you might have a 3' tall plant after 3 years.

With annual pruning you can likely keep them to 4'. Why not put them where you don't have to stress them and limit their potential and get something that fits the space?

Thanks Whaas.....
I prune back my blue hydrangea (not sure what kind it is)
every year because I don't like the sticks showing during the winter. It seems to grow back just fine the coming year. Are the paniculata different?