GENERAL RULES of SEED SOWING in Soil 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 & air are a must. Cover seed with about 2 times their thickness of soil. Sow shallowly in cold wet spring, more deeply in warm dry summer. Large seed can be soaked overnight and planted singly. Barely cover small seed. Lightly tamp soil to insure good contact with the seed, 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 pretreatment. Common causes of seedling loss are damping off due to poor air circulation & overwatering, drying out or burning due to placing in full light or outdoor conditions too quickly, transplanting shock (best done on a cool, moist day), and predation by insects, slugs and snails at night. TEMPERATURE Most seeds germinate best at warm (70°F) temperatures. Plants from temperate regions, the arctic, high mountains and high deserts often germinate best at cool temperatures. Plants from winter-rain areas like California, the Mediterranean, Chile, S. Africa and parts of Australia also like cool temperatures. Warm temperatures will often speed germination of these seeds, but lower vigor & survival. TIME UNTIL GERMINATION Average range of time to germinate is usually given in weeks. A seed that takes 2 - 3 weeks will usually come up fairly evenly; one that takes 1 - 12 weeks will tend to straggle in irregularly. Time varies with temperature, so expect considerable variation. Don't give up too soon- many who have given up and sown another seed in the pot end up with two types of plants in the same pot! SOIL MIXES Many seeds do well sown direct to ordinary garden soil, but even good soil may be poor in pots or flats. These need a lighter, looser soil. Most commercial mixes are fine, but the addition of some garden soil and compost will often insure adequate beneficial micro-organisms & fungi, A good soil mix can be made at home from 1/3 garden loam, 1/3 peat or compost, and 1/3 gritty sand. HARD SHELLED SEED These have hard impermeable shells and need nicking or scratching the coat to allow water to enter and the seed to germinate. The best results are from the least amount of nicking that will allow water to enter and the seed to swell. Many failures are due to over-nicking and damaging the seed. Different seeds need varying amounts of nicking. Most do best with lightly rubbing on sandpaper or a file until just the very outer coat is scratched. Often just scratching with a knife-point or scriber works. Nicking seed one by one can be tedious but is most effective. Larger lots can be rubbed between two boards covered with sandpaper, or shaken or tumbled in a can lined with sandpaper. Then soak the seed overnight and any that don't swell or soften should be re-nicked and soaked again until swollen. NICK & SOAK means nick first, then soak, and re-nick any hard (unswollen) ones. SOAK & NICK UNSWOLLEN means the seed is usually only partly hard and many will swell without nicking. Soak first, nick only the hard ones. ABOUT DIFFICULT SEEDS Over millions of years, wild plants have evolved germination strategies which ensure their survival, but which may not be convenient for the home gardener who wants a quick and even stand of plants from a packet of seed. Many seeds sprout irregularly, so that if the first flush of seedlings is killed by adverse weather, insect predation, etc., more will come along to take their place. In adaptation to various environments, some seeds need periods of cold, warmth, darkness or light, fire, etc. Some have seedcoats of varying hardness or impermeability. Many seeds have internal clocks, and give much higher germination at certain times of the year, regardless of the treatment given. All seeds wait for the correct time and conditions before sprouting, and the gardener must mimic those conditions to ensure successful germination.