Eesh, lost my post to you and had to start over.
Although I grow thujas, I'm only growing the Eastern variety and two cultivars of same so take anything I type with a grain of salt. I took a peek at 'Green Giant' and found the parentage to be standishii x plicata. Its popularity stems from its rapid growth rate as well as its pyrimidical shape and narrow spread. I get real nervous when I see any tree with that type of a growth rate. Yes, they claim you can knock out noise from neighbors while creating privacy but it's not generally in one's best interests to create a soldier row of any plant and particularly one consisting exclusively of trees with that type of a phenomenal growth rate. Remember, information on the web is created to make you part with your money. They want you to be impressed with what you read so you buy the plant to create screening for your yard.
Barring your USDA zone of 8 which is very different from the USDA zone of 8 out east or even further west from where you are, I get this feeling that plant might not be all that happy where you garden even if you water it well on a regular basis. T. standishii is from the mountainous regions of Northern Japan which is probably why 'Green Giant' is stated as being able to withstand heavy ice and snow loads. I've seen it growing in Hokkaido and it is magnificent to say the least but when you think of Hokkaido, think Minnesota. That is a northern reach of Japan. T. plicata is from the PNW. I know about hybrid vigor and all and I read from the Botany Shop that they're shipping these trees to CA where they do well in warmer zones but that's not the desert. Makes me nervous that you might end up with an incredibly stressed tree. Maybe select a few other species that might be better adapted to your region and associated rainfall or lack thereof?
Speaking of the desert, we were just out your way for a few weeks. Although we had been to Taos to ski in the past, we'd never taken the time to explore anywhere else other than the shops of Santa Fe and surrounding area. We loved the Gila National Forest down your way. We also loved Los Alamos, Nageezi, Pecos, and Eagle Nest. Cimarron State Park is a native flora and fauna gem and so expansive. I had no idea your state was so diverse and beautiful. We were particularly enamored with the Tsankawi Ruins Trail of Bandelier National Park. NM blows my area of Illinois out of the water!