Here is complete guide about Dawn Redwood gardening found in the book called “TREE AND SHRUB GARDENING FOR NORTHERN CALIFORNIA” by “Bob Tanem” and “Don Williamson”,here is an excerpt from the book
Features: foliage, bark, cones, buttressed trunk Habit: narrow, pyramidal, deciduous conifer Height: 70-125’ Spread:
15-25’ Planting: container, spring, fall Zones: 4-10
IN MY FIRST YEAR AT THE UNIVERSITY OF CALIFORNIA IN 1949, three of the university’s botanists discovered fossilized seeds of this plant in China. A front-page story heralded when the botanists were able to sprout three of the seeds they had brought back-a seed from the Jurassic era could be viable! Subsequently, a whole forest of these trees was discovered, and vegetative propagation has made them available. The three trees from the original seeds still exist: two are on the grounds of the University of California, and one is located at the post office in carmel.
Growing
Dawn redwood grows well in full sun or light shade. The soil should be humus rich, slightly acidic, moist and well drained. Wet or dry soils are tolerated, though the rate of growth will be reduced in dry conditions. This tree likes humid conditions and should be mulched and watered regularly until it is established. It does not tolerate salty winds or desert conditions.
Pruning is not necessary. The lower branches must be left in place for the buttressing to develop. Buttressed trunks are flared and deeply grooved, and the branches appear to be growing from deep inside the grooves.
Tips
These large trees need plenty of room to grow. Larger gardens and parks can best accommodate them. These trees are attractive and impressive as single specimens or in group plantings.
Recommended
The cultivars do not differ significantly from M. glyptostroboides. Both ‘National’ and ‘Sheridan Spire’ are narrower than the species. These two have not been in cultivation long enough to have reached their mature heights, but they are expected to be as tall as the species. (Zones 4-10)
Problems & Pests
Dawn redwood is not generally prone to pest problems, though it can be killed by canker infections. Keep ants out of these trees.