Chilling Seeds (Stratification) for Better Germination
Fall is a great time to start seeds that need a cold treatment, known as stratification, to break dormancy, sprout and grow.
Sow seeds at the recommended depth in pots or trays filled with a well-drained potting mix. The planting depth for most seeds is usually twice the seed diameter. Gently water the potting mix and cover the container with plastic to keep the potting mix moist.
Move the pots and trays to a location where the temperatures remain around 40 degrees for at least four to eight weeks. An unheated garage, porch or coldframe can work but should be monitored since the temperatures in these locations are influenced by the weather outdoors. A spare refrigerator is a perfect alternative since the temperatures are constant.
Once the weather warms or the seedlings start sprouting, remove the plastic, move to a sunny location, and water as needed.
A bit of information: Don’t be alarmed if the seeds do not all sprout at the same time. Some seeds will start growing soon after the weather warms or they are moved to a warm sunny location. Others may take several weeks to a month.