I have them centered about 10 foot away from the fence. And about 10 foot from the patio. I have four planted so far but ended up putting them 8 foot from centers. But then I went out and read up more on it and found that some people were only spacing them 5 foot.

5' on center at a minimum.......8-10' is better. You should only consider a closer spacing if you are planning on a sheared hedge.

The singular issue with any sort of privacy screening is that it takes time :-) Unless one can afford to purchase and plant almost full grown specimens, one needs to allow sufficient time before the plants grow large enough to provide the screening desired. And it is not always easy to predict your privacy needs 5-10 years down the road!

Planting closer can speed up that wall of privacy some but not a good practice for the long term health of the trees.

So you think I should be fine at 8 foot centers as far as "mature" privacy? I kept thinking they would still mature have huge gaps at the fence line and be pointless. lol

Yes. The GG's grow wide just about as fast as they grow tall. And while it will depend on location and growing conditions, a spread of 20' or more is not uncommon for mature GG's.

when the goal is sight block.. you plant them to achieve your goal ...

when you are planting individual specimens ... then you plant them further apart ...

if the former.. you want them to grow together asap ... in the latter ... you plant them so they maintain.. to some extent .. their individuality ...

8 foot on center.. means that each tree need only grow 4 feet toward the other ... and that isnt much.. for these... GIANTS ... and frankly.. imo.. there is little difference between 5 or 8 feet .... 2.5 feet each vs 4 feet ... and with these GIANTS ... once established.. that might be not much more than a year or 3 ... depending where you are ... the length of growing season ...

frankly ... you are over engineering the concept ... rather than gardening the concept ...

when it all boils down ... lol .. you might be better going off with what wifey said .... this probably isnt where you should draw some line in the sand ...

and keep in mind.. with trees.. we think in tree time .. which is counted in decades ... it will take them a year or 2 to settle in from transplant shock ... and then a few years to start putting on the height you want ... which is the norm .. just dont go all instant gratification on them.. and it should all work out ...

ken

Thank you both for the help. It makes me feel much better now as I obviously was a bit confused. I also did not want to squeeze in more, or try and move them as I am guessing it wouldn't be a good idea health wise.

The U.S. National Arboretum presents Thuja 'Green Giant', a large, evergreen sentinel in the landscape

https://www.usna.usda.gov/assets/images/as_standard_image/Thuja_Green_Giant.pdf