Many tree seeds do benefit from
stratification, which is a process that overcomes the seed's dormancy and promote germination. To understand this process it helps to have an idea of what a seed is.
please refer to the diagram
here
Each seed contains a tiny embryo, with a food source that will provide energy for the plant to develop until it has sufficient leaf area to begin photosynthesis on its own. The embryo and food are surrounded by a
seed coat that varies in its toughness and resistance to moisture, leading to different requirements for stratification.
Why do seeds need to be stratified? Plants have developed to maximize the probability that the species will survive over time, and dormancy is a mechanism to ensure that some seeds will persist until conditions favorable to germination arise. Fire in a conifer forest, for example, triggers the cones of many species to open and release seed in abundance.
While some seeds like citrus, for example, should be sown immediately, many seeds benefit from a period of cold stratification that you can accomplish easily by wrapping the seeds in a *slightly* damp paper towel, placing them in a ziplock bag, and storing them in the refrigerator at a temperature just above freezing for two months or more.
Seeds with extremely hard husks are sometimes treated by cracking the seed coat or sanding it a bit, nipping the hard husk with a scissor or cutter or scoring with a razor.
In an environment like New Jersey, you might just sow your seeds in late fall and let winter take care of the stratification process for you. If you let me know which species of seed you are planting, I'll try to provide more specific information for you.
here are some additional suggestions for
Storing seeds to help ensure future viability.
Regards,
Dr.Bonsai