Peppers are tropical plants and require a sustained soil temperature of about 80°F to germinate. Even under optimum conditions, most sources agree that pepper seeds started in a soil-less mix will not sprout in less than 7-10 days. The real trick with starting pepper seeds is to raise the temperature of the starting medium without denuding the medium of moisture. Airflow is another important factor in sprouting all types of seeds, so the growing medium needs to accommodate this condition as well. Furthermore, the conditions that favor pepper seed germination can also encourage mold to form which can smother new seedlings.
Although the challenge of starting peppers from seed seems formidable, we know it's not only possible but quite commonly accomplished by home gardeners, including ourselves. We grew about 50 pepper plants last year from seed and are hoping for similar success this year. The main difference for us this year from last is that we are growing a larger variety of peppers this year but a smaller number of each type. This means that we will be starting fewer seeds per variety and need to achieve the best germination rates we can get. We don't want to repeat last year's experience in which we ended up with way too many plants and not enough space to plant them. In other words, we would like to fine-tune the seed starting process and develop a clearer picture of how many seedlings to start with in order to arrive at a target number of adult plants. We expect to repeat this refinement process for the other vegetables we will be growing as well.