Chances are excellent that your transplanted trees are short of water. This is true whether they were dug from one place and moved to another or even if they were only moved from containers into the ground.

You can verify the soil moisture content by sticking a finger into the rootball which was transplanted. Is it wet, moist, or dry? The entire rootball must be kept evenly moist until the roots extend into the surrounding soil.

Also check the moisture content of the soil surrounding the rootball. It, too, must be irrigated on a regular basis but less often than the rootball simply because the roots aren't out there as yet.

A regularly scheduled series of irrigations is required to help a newly planted tree to develop a vigorous, sturdy root system which will be able to support the tree’s needs for many years. The goal is to gradually work toward the basic requirement of an established tree.

A rather detailed irrigation schedule is recommended for the first 2 years of the tree’s life in its new site. The larger the tree when it was planted, the longer it will need supplemental water to develop its root system. Because of the size of your trees, plan on at least 3 years.

To help reduce water loss, you might also rig temporary shade and windbreaks as protection through this summer.  

This information will help you plan for the supplemental water your trees need: “Watering newly planted trees and shrubs” - https://www.extension.umn.edu/garden/yard-garden/trees-shrubs/watering-new-trees-shrubs/.

Thanks for the information.  Two follow-up questions:
- How wet is too wet?  What symptoms would the trees have if they were too wet?
- Will the brown branches return to green or are they effectively dead?
Thanks.

Too wet is sopping wet, or outright muddy.

If the roots were too wet for too long, needles would go off-color and branches would dieback. The effects of too little water are similar. If the condition is not corrected, the tree will eventually die.

When you water an established tree, the goal is to moisten the entire rootzone to at least 8 inches deep. With transplanted trees, you must regularly water the entire rootball which was set into the new soil, as well as occasionally watering the surrounding soil.

If the trees were dug from elsewhere in your yard, they have the extra complication that they have lost many roots.

With conifers, brown is dead.

But delay removing the dead wood as long as possible to allow the tree to indicate what is truly dead. You would be wise to wait until next spring.

Thanks for the update. Two suggestions: remove the supports around all of your trees. They should not be left on over a year. Allowing the tree trunk to move in the wind eventually strengthens the trunk so it is more flexible. Second, add some organic compost around the trees’ trunks, but not touching the trunks. The compost is nature’s time-release fertilizer, and our current rainy weather will wash the nutrients into the soil and to the roots. I cannot tell from the earlier dialogue whether you put any compost in the planting hole, or whether the clay was adequately broken up. It’s too late to change those, but your tree may still be in need of nutrients. Good luck!