I'd guess lower humidity / higher sunlight levels than they are adpated to in the wild might be significant

Resin

All the redwoods and sequoias I've planted have needed shade and lots of water. Redwoods in my yard are very hard to grow and I've lost several. Lots of money down the drain. The coast redwoods also don't like it too hot or too cold. The sequoias seem a bit more hardy temperature-wise but they also brown in hot sun and brown in winter freeze.

I've let willow suckers grow wild and fast so this yard will have a bit of shade to give the redwoods and sequoias a chance. In fact many trees from 6" to 10' have needed shade in order to survive transplanting and get used to the yard, adapt and hopefully establish.

Those trees growing under other trees are noticeably greener and more robust than those out in the open.

If enough survive, in a few years there won't be an "open" left in this yard! I've overstuffed it with potentially giant trees and one reason is desperation for shade.

People with old big trees have no idea how lucky they are. Trying to get a treed yard from scratch is really hard and slow. It drives me insane when ppl cut down a tree. They have no idea the incredible value and blessing and miracle of an established tree.

I've had just the opposite experiene here. Dawn Redwood seedlings here in the mid"west" I place in full sun (it gets very hot as well as very humid here) for three months so I'm surprised at reading this. First-year right out of the winter greenhouse that is however.. maybe that's the difference. I grew them for 3 months in a nice cool environment with "full sun."

hmmmm.

Dax

My experience is with Dax. I have a row of Metasequoia glyptostroboides, Dawn Redwood, and they start in full sun and trail off into mostly shade. The ones in sun are 3 times the height of the ones in shade, almost like the long end of a triangle side. The sun ones are growing in rocky, dry soil, where the shade ones are growing in dampish peaty soil. None of the new growth is ever burned, however, once the bright green new growth comes out, it gets very humid here, so maybe that's the key.

You'll always find individual cases that confirm the rules or are exceptions to the rules. However, what it may come down to in many cases is the roots. How developed are they? Can they effectively move water from the soil into the foliage under stressful conditions? even where soil water is optimal? Is the soil sufficiently loose that the the roots can breathe?

It can take several years for roots to sufficiently develop. We've tried lots of conifers over the past eight years in our hot, dry steppe climate. It's been interesting to watch individual trees do better and better each year as they grow, and presumably develop better root systems. Suddenly one year they will just take off.

I have a 5 year old metasequoia in my front yard. The soil is fairly moist during the raily seasons and I assume rich (from my septic tank up the hill lol) because the grass grows excellent there. Thanks to the slope of my hill and the tree line across the street Its summer sun exposure is about 0900 to 2000 (6PM).

Only thing that's cause a little die back are untimely frosts. Lost about ten inches of top growth once in the spring and then another fall. Guess its approaching 3meters (15 ft) tall now.

I planted a Dawn Redwood 20 years ago in my backyard. Today it is 60 feet tall and last year produced hundreds of cones. I have about 100 seedlings that range in size from 1 inch to 12 inches in 5 months of growth. I had about 10% germination. I planted in several different soil conditions and different sun locations. I have concluded that full sun with daily watering is the most effective combination for growth. Seedlings growing directly next to each other have different growth rates. I have no significant browning of leaves in full sun. I will begin planting the strongest seedlings in the ground next year and continue pot growing the remaining until they have enough root structure to support them. My original tree (purchased as a 1 year old seedling) started slowly and then after about 5 years exploded with a 5 foot a year growth. It did not seed this year much to my disappointment. I think I have found the right combination of growth factors through trial and error. I am hoping to get another chance soon. For those who wish to grow only a few trees I suggest ordering seedlings from a grower. They will have the 1st year of growth out of the way and will be much more likely to survive.

They burn in the full sun because they evolved to grow under the shade of their extremely tall parental trees. Think about what a sequoia forest looks like. It's all shade at ground level, some dappled sunlight during the height of the sun, rightwhere all the seedlings would naturally germinate. It only makes sense that when they are young, they would do best in the full or dappled shade.

Uuuummm Yeeeaaaahhhh. What Embo. said is correct; both species are doing fine for me in full sun. This climate almost never has hot dry air and low dewpoints in summer, but neither it is misty and cool by any stretch of the imagination. I'm sure young Sequoias even in the central Valley do fine in summer, newly planted in full sun, if irrigated. I commented in my recent trip thread about how overplanted they seem there. It's probably when they get really big and their net demand of water per unit land area goes way up, that they start to look ratty.

Although considered borderline in this area Sequoia sempervirens is far more tolerant of winter sun than most cultivars of say, Camellia japonica. Though again it is never (precip) dry here in winter and I established the plants correctly. (As I found out when I moved one recently and discovered it had created an absolutely huge, thick root system) I'm not sure they'd be so trouble free in, say, Albuquerque.