Seeds need water and oxygen to germinate, so are best started in a light, loose soil that will not compact, get soggy, or crust over. Free flow of water and air are necessary. Cover seeds with 2 – 4 times their thickness of soil, unless they require light to germinate. Sow shallowly in cold wet spring, more deeply in warm dry summer. Large seeds can be soaked overnight and planted individually. Barely cover small seeds, and sprinkle fine seeds on the surface and water by misting. Plant flat seeds edgewise and winged seeds with wing uppermost or broken off. Sowing too thickly wastes seeds and weakens the crowded seedlings, but some kinds sprout best if crowded. Lightly damp soil to insure good contact with the seeds, unless heavy. Keep soil moist, not soggy, and do not allow to dry out.
Common causes of failure are soil too heavy, wet or cold, or allowed to dry out, not giving slow seeds long enough to come up, pests eating the seeds or seedlings, and not giving dormant seeds the proper pre-treatment. Common causes of seedling loss are damping off due to poor air circulation and overwatering, drying out or burning due to placing in full sun or outdoor conditions too quickly, transplanting shock (best done on a cool, moist day), and predation by insects, slugs and snails at night.
Average range of time to germinate is usually given in weeks. Time varies with temperature, so expect considerable variation. Don’t give up too soon!!