Seed Stratification

Stratification is a survival mechanism so that seeds do not prematurely germinate.

It helps the seed break dormancy and initiates the germination process when

growing conditions are favorable. When collecting seeds in the fall, stratification

pre-treatment is necessary to mimic the natural conditions seeds would

experience in the soil over-winter.

Seeds of many trees, shrubs and perennials germinate best when pre-exposed to

both cold and damp conditions. Moist stratification is a process where seeds are

mixed into a moistened inert material, such as sawdust, sand, vermiculite or peat

moss, or placed in moist (not wet) paper towel. They are then put into a plastic bag

or sealed container and stored in a refrigerator for 10 days to 3 months. Be sure to

label the containers or bags. Check the seeds regularly for correct moisture levels

or sprouting. After this, they can be sown into pots.

Dry stratification is achieved simply by subjecting the seed to cold temperatures

(0˚C or lower) for a period of a month or longer. This can be accomplished by

putting the seeds in a freezer, or storing them in a rodent-proof container in an

unheated building for 30-120 days.

When purchasing seeds from a reliable source, the stratification requirements are

usually mentioned on the seed packet. When collecting and saving seeds, it is

always a good idea to research any germination needs.

Submitted By Brenda Gallagher