The Natural Stratification Method- Fall Sowing Seeds:
The late Fall sowing of seeds directly into a garden bed or pot for eventual germination the following Spring will naturally satisfy a seed's requirement for just about any and all cold stratification, providing of that the natural conditions and needs of the dormant seed are actually met. For areas of the U.S. where there is very little resemblance of a winter, deeply dormant seeds should be cold stratified in your refrigerator.
Nature's Method means you can forego the cold stratification, as the overwintering of the seeds in the earth or a pot of potting soil out of doors will accomplish the same thing as refrigerator cold stratification. Usually the results are as good, if not better than those resulting from seeds which have undergone an artificial cold stratification. It is a widely practiced means of germination by professionals, not to mention Mother Nature. 

If you are dealing with seeds that are recommended as needing some warm stratification prior to cold stratification, then they should be sown a few months earlier than late Fall. These seeds often have thick hard coats. In some cases, it also has an effect on the embryo. Scarification prior to Natural sowing this type of seed in mid Summer to early Fall helps the natural process along and lessens the length of time needed for effective warm stratification. 

We use both the artificial and the natural method of stratification. If done right and you are lucky with seasonal conditions, both are quite effective.



A Few Key Points on Germination:
Seed germination is a bit of an art.  A green thumb and experience can help.
Pretreated seeds prefer moist, warm conditions for germinating, not wet or sopping wet, cold conditions.
You will quite often find some batches of seeds sprouting before you expected. Some will sprout later than expected.
Be patient when cold stratifying seeds. Give them the recommended time and a bit more for good measure.
Always use clean/new potting soils and pots.
Don't over water your seeds or seedlings! Watering from the bottom where flats or low pots in trays are can ameliorate overly wet soil surfaces that can be caused by watering from the top.
Remember that pots need more frequent waterings then garden beds, as they dry out faster. Terra cotta pots should be soaked before using.
Give your seedlings half or quarter shade from the sun. Many deciduous plants cannot handle full sun when they are seedlings. 
Make sure to check light requirements of seeds. Some seeds need light to germinate.
Don't give up on any seeds that did not germinate immediately after planting. This is a frequent outcome and they will most likely sprout the following Spring.


Specific Germination & Stratification