These are privately-owned lands where redwood mills and tree farmers have planted and grown redwood trees specifically to be harvested. 5 Trees over 200 years old are usually considered old growth. Land that can sustain and nurture redwood trees is extremely valuable and the private owners take good care of this resource. State law requires it and good business practice dictates it. The species' own tenacity probably does even more to regenerate the redwood forest than the planting of seedlings.
Redwood is the only softwood in the country that sprouts from stumps.
These new young trees grow quickly, thriving on the existing, mature root system. In some areas, early pioneers were actually unable to clear redwood forests to make pasture land. The trees kept returning in spite of all their efforts. Today, California's forest-practice law, the strictest in the nation, requires that every harvest operation must be reviewed in advance and approved by the State Department of Forestry. If an adequate number of trees are not left on the harvest site to make up the new forest, state law requires the landowner to replant to assure that a new stand is established.