Few better than H. paniculata 'Limelight' for a full sun hedge. These bloom in July if you don't prune too late. You can keep the dead blooms on all winter if you like (Google image search that).

Use the following link for a walkthrough and other useful information.

Here is a link that might be useful: Limelight Hedge information

Thank you! I was thinking limelight. I do like the mophead varieties but for a beautiful hedge I would go for the limelight.

What about incrediball?

If Limelight is a no go then I'd use any of the paniculatas, or better yet use them all and mix them up. That way if/when one dies and needs to be replaced it won't stick out like a sore thumb. And eventually you will lose one.

I love Limelight and have many in my yard. Would't be without it! And I think the dried blooms look great in the winter.

Quick Fire is another to consider if you'd like something that blooms sooner. Bees and butterflies love it too.

I also really like Incrediball, although none of mine is in sun all day. It would be a little fussier about having enough water than Limelight or Quick Fire, I think.

I've seen one that was a mixture of Limelight, Quickfire and Vanilla Strawberry. Very nice.

Oh I like that idea of mixing Quickfire and Limelight so you have flowers for longer. How would you alternate?
Also, about when (what month each year) do they come in and when do they flower? Just wondering how many months I would have privacy from the neighbors!
Thanks!

I believe they both bloom midsummer to fall.

Kate

I'm in zone 5b & have 4 Incrediballs in full sun - not a good idea! They're planted next to a rose bed & get a ton of water. Mine have grown really well & are healthy, but the blooms (which are huge!) go from pale green straight to brown, never turning white. I think they are 'sun burned'. I had planned to move them this year, but didn't get a chance. I'm definitely moving them to a shadier spot next year!

IME any of the H. paniculatas would work, or as others have suggested, a mix of them is a really great idea. Here they have thrived in full sun without irrigation, unlike the H. macrophyllas and H. arborescens, which like afternoon shade and periodic water. I would visit nurseries and look at the flowers of various types of H paniculata since the panicle's shape, density, and color varies a lot. I have Quickfire and Pinky Winky and prefer QF: the longer bloom time, the looser and more rounded panicles, and the color, which starts with white flowers around July 7-11, slowly shifts through a pale pinkish, and ends with a glowing cerise that lasts until hard frost. Pinky Winky starts later, has very dense pointed panicles, and still has a lot of white at this time of year. I am not overly fond of Limelight's fall color fade, though the summer is stunning, so having it as part of a mix would be a way to emphasize the positives of each while letting the less attractive aspects fade into the background, letting the ones that are at their best capture attention.

My H. paniculatas leaf out with the majority of the other deciduous woody plants in my area, not early or late, so you will have time in the spring when you want to be outdoors but they don't provide as much privacy.

My computer is in for repair, so I don't have normal access to photos, but I will look for some and add to a followup.

Quickfire (with Clematis Little Bas growing into it.
June30

July 9

September 24
{{gwi:277271}}From 2013

Pinky Winky
Sept. 24 on far left of photo
{{gwi:278655}}From 2013

I haven't uploaded any earlier photos of PW.