It's easy to find the seeds of a redwood tree, or Sequoia sempervirens, because each mature tree produces up to 8 million of the tiny seeds every year. The hard part is finding seeds that will sprout -- most are not viable. These majestic trees are native to the northern California coastal mountains and extend into Oregon. They do not adapt well to other climate areas, and because of their size and habit of dropping needles, cones and branches, they are not appropriate for suburban yards.
Collect redwood cones from the ground near an existing tree in December or January. The cones fall in winter but do not immediately open, so collecting them at this time ensures the maximum number of seeds per cone.
Dry cones for three to five weeks in a warm, dark, dry, well-ventilated area. The scales should begin to separate during the drying process. When this occurs, remove the seeds from the cones by shaking cones over a piece of newspaper.
Fill one or more nursery flats with clean potting soil and water until the water runs out the drainage holes. Then scatter at least 20 seeds on top of the soil. Barely cover them with a sprinkle of additional potting soil. Sprinkle with water again.
Insert your seeded flat into a plastic bag, and seal it with a rubber band. Keep it in a cool area that does not receive direct sun. Remove the flat from the plastic bag every few days to water it, making sure you keep the soil moist at all times.
Remove the flat from the plastic bag when you see green sprouts emerging from the soil. Keep the soil moist, and continue to grow the seedlings in a cool spot that receives only indirect sunlight.
Transplant seedlings to gallon-size nursery pots with drainage holes when they are 4 to 5 inches tall. Keep the soil moist, and mist the tips of the seedlings every day to give them the humidity they receive from fog and rain in the wild.