Step Three: Classes stratify seeds in their classroom and store their seeds in a cool, dark place.
“Seeds from plants native to temperate zones possess a remarkable survival mechanism: they require a cold period to germinate, a tactic that occurs naturally in the garden during our winters. This makes evolutionary sense; otherwise, fresh seed would germinate in the autumn, and the young seedlings would succumb to icy blasts.” – Canadian Gardening
However, seeds in the wild are often destroyed before they can germinate. Gardeners help seeds break their dormancy without subjecting them to the risk of rotting, being eaten, or simply landing in inhospitable soil.
“Stratification involves soaking and chilling seeds prior to sowing. This simulates natural conditions where the seeds would remain through a winter on cold, wet ground. Seeds will usually germinate promptly and uniformly after stratification. Unstratified seeds may take up to two years to germinate, if they do so at all.
In the wild, “seed dormancy” is usually overcome by the seed spending time in the ground through a winter period and having their hard seed coat soften up a bit. By doing so the seed is undergoing a natural form of “cold stratification” or pretreatment. This cold moist period triggers the seed’s embryo, its growth and subsequent expansion eventually break through the softened seed coat in its search for sun and nutrients. In its most basic form, when we control the cold stratification process, the pretreatment amounts to nothing more than subjecting the seeds to storage in a cool (not freezing) and moist environment for a period found to be sufficient for the species in question. This period of time is often and usually found to be somewhere between 1 through 3 months.” – Back Yard Agora
As part of Step 3 of the “Wild” program, classes help seeds mimic winter by cold stratifying them in their classrooms – placing the seeds in soil in seed trays, covering the seed trays with a dark material, and labeling and storing their seeds in a cool dark place – either outside the school for about 6 weeks in winter, or in refrigerators.