This seed must be stratified. Place seed, with moist sand and peat in a small polythene bag and seal. For wet-cold stratification, simply place these bags in a refrigerator just above freezing. For warm-wet stratification, store at room temperature. After the stratification period, sow the seed.
Some seed has a double dormancy, which normally is a combined seed coat and embryo dormancy.
This is again characteristic of many trees, shrubs and perhaps some alpine plants. Complex manipulations may be needed to stimulate germination. The majority of suggestions for seed germination are for indoors in the early spring. To start the seed indoors, sow seed shallowly, as many seeds are light sensitive. Use a sterilized soil mixture, as this may prevent seedlings from damping off.