Fog
One myth of redwood trees is that large amounts of fog are a necessary element for redwoods to reach their growth potential. While fog is, in fact, essential for such growth in areas like northern California's redwood belt -- where the wet season is notably shorter than that of other redwood locations--other methods can be substituted for the moisture received from dense fog. In Western Oregon and Washington, greater amounts of rainfall produce substantially sized redwoods; New Zealand redwoods have thrived on irrigation methods and grow up to 220 feet.
Age
One common rumor is that coast redwoods commonly exist that are more than 2,000 years old, perpetuated by the myth that the redwoods, collectively, were around "when Christ walked the earth." On the contrary, it is unlikely that any tree in Redwood National Park is even as old as 1,000 years, and even though a single coast redwood was once discovered that was more than 2,200 years old, those over 1,800 years in age are an incredible rarity.
Growth Speed
It is a myth that coast redwoods take hundreds of years to grow. In reality, ideal conditions allow for much more rapid rates of growth than this. In certain California locations, coast redwoods have been known to reach 170 feet in only 50 years. Ideal conditions -- including such details as sufficient moisture, adequate ranges of temperatures, protection from wind and ample spacing -- allow for redwood growth of up to an inch per year.
Great Heights
Another myth of redwood growth is that coast redwoods can reach their great heights only in the West; growth of such trees in the east will always pale in comparison. In fact, limiting factors on the East Coast are similar to those on the West Coast, such as amount of wind exposure, and there has been at least one recorded instance of an East Coast redwood growing to be greater than 100 feet.