Seed Stratification

Seed Stratification is the process of storing seeds in a manner that simulates the natural environment the seed would experience outdoors over the winter months, and before sprouting in the spring. Stratifying seeds is a process similar to the dormancy period for fall bulbs, where the bulbs need a “chilling period”, before blooming in the spring.

In nature, seeds drop from the mother plant in the fall, and lie on or slightly below the ground over the long winter months. Often, they are covered with a thin layer of leaves or other dead plant matter. During this time of dormancy, the seeds are naturally conditioned, so they are ready to sprout in the spring. Some, but not all seeds require this stratification process, to successfully germinate.

Most commonly perennial flowers, and many fruits, require stratification.

What Seed Stratification Does

Simulates natural winter conditions of cold, often freezing, and wet soils.
It softens the seed coat, making it easier for the seed embryo to emerge.
Creates cracks or splits in the seed coat, allowing moisture to reach the embryo.
This cycle, followed by a warming of the soil, triggers the seed embryo to sprout.

How to Stratify Seeds

Method #1: Take mature, dried seeds and place them in a sealable baggie. Seal the baggie. Place the baggie in the freezers for several weeks, or longer.

Method #2: Place seeds in moist soil, sphagnum moss, vermiculite, or sand. The material should be damp, not wet. Place it in a cold, dark, but not freezing location. It is important that the material and seeds remain cold. If it warms up, the seeds may sprout prematurely.