Both Nicotiana tabacum and N. rustica have been cultivated for easily over 1000 years. Neither spontaneously release enough seed to self-propagate a stand for more than a few years. This is not true of all the other species of Nicotiana, which are easily capable of growing wild in sustained patches.
As far back as two hundred years ago, planters in all parts of the world directly seeded specially prepared outdoor seed beds, often beneath the shade of trees. Seedlings were then selected from that to transplant into full-sun growing areas. This practice improves the stand and spacing of the plants, but it limited tobacco growing to those areas with a long enough growing season to allow germination in late spring through harvest before the first frost.
In southern California, depending on your elevation, you may have a long enough season to do it this old fashion way, but it's not nearly as efficient as starting the seed indoors. Outdoor seed beds really do require considerable attention and protection, since the emerging seedlings are relatively low in alkaloids, and are eaten by numerous insects and animals that would shun the alkaloids present in a 6" transplant. Also, outdoor seed beds are more subject to the vicissitudes of the weather, with all the fungal implications that go along with non-ideal conditions.
Bob
