Giant redwood tree seedling tips drying/dying

Hi everybody,

I have this problem. I was growing some giant redwood (Sequoiadendron giganteum) seedlings under some grow lights. When they got rather big I replanted them in bigger pots (used a very nutrient rich media) and brought them on the windowsill at my work. Stupid me did not though about the intense sunlight. They stood there for close to week I think and I noticed the tips not looking good. They started to seem dry and brownish somewhat. I then brought them to a shaded place, yet the tips are dying back more and more where for one of the plants it's already the whole branch.
The questions are as follows:
1. Is this really a sunburn or is it something else, like the replanting? Beside the sunburn my guesses were nutrition burn due to nutritious media or very dry air in the office I have them (although I have other plants here that are doing fine so doubtful about that).

Would like to know for the next tries if these ones do not survive.
2. Can they recover, or they are gone at this point and the damage will kill them?
I'm attaching some pictures of the branchlets and the whole plant

The first thing that comes to my mind is humidity. Redwoods aren't like most trees — they get water from both their root systems and their needles. Is the new location much drier than the old location? Have you tried spraying the tree with water on the needles every day? It looks an awful lot like it got dried out and burned to me. I doubt the damage is permanent, trees are pretty resilient.

I second Kyle's assessment they got dried out too much and then sunburned.

To save them, pinch off the damaged portions and set a tray with rocks and water under the containers, they will make a comeback.

Sequoia can do well in not so nutrient rich soil, but unless you gave them too much nitrogen, that would not be the issue here.

I planted one of these seedlings in 100 foot deep topsoil (we lived in a flood plain and I actually did measure the top soil depth), it took off, growing 6 feet a year until it got so large the new house owners had to cut it down to save the road.

I plan on putting a few at the back of our property soon, it will be super cool to see them towering above the mountain top in about 10 years from planting.

Thanks a lot for you replies. I will try to save them. Will mist them and try the tray method. One of them are pretty bad, but hopefully has enough saved up energy to spring back to action. We will see how it goes in the next weeks.

I agree with the advice and just add that I live in the redwoods and the humidity around here rarely drops below 60 percent or so. For a lot of the year it is closer to 80 percent and I am in a cleared neighborhood area not deep in a grove of the trees. They like it very very humid. The trees near me are sequoia sempervirens, I'm not totally familiar with your species so it might well not need as much humidity, but I would guess it still wants more than you would expect.