I have tried for 4 years to cultivate Green Giant Thujas for a privacy fence because of their reputation for fast growth and low infection issues. Last year temps got bad up to the 105s and with no shade until late afternoon I lost 2 of 5 with the last 3 heavily damaged. This year I really thought I had a great plan. I put up shade sails in early summer after planting 4 more Thujas in early March. But even completely covered I've lost 3 of the 4. The 3 from the pervious year are still alive under the same shade but they are still half dead from the year before. I honestly didn't believe they could die under complete shade getting water 3 times a week but they did. We have had some really tough temps. Upper 105s for about 20 days and apparently its just too much for these so please keep it in mind and ALWAYS get your trees from someone who will insure them for a year. I'm going back to Leyland Cypresses which zones go all the way to 10.