Q: I wish to plant some seeds to grow magnolia trees. I have heard various stories about refrigeration and splitting the seeds. What exactly needs to be done to ensure successful germination?
A: Many woodland plants have seeds that need a period of moist, cold weather in order to germinate. A hundred years ago, apple growers would collect and plant the seeds from their most productive trees in order to improve their orchard. They found that by keeping their seed between 32 degrees and 45 degrees Fahrenheit for three months, almost all would sprout. The seeds might otherwise germinate sporadically, if at all. Scientists discovered that many woody plant seed require being chilled in a moist environment before they can send up a sprout. The process of moist chilling is called “stratification” because the farmers would layer their seeds in damp peat moss before they refrigerated them.
Your magnolia seed need to be stratified in order to have most of them sprout. Simply collect the seeds and mix them with some barely damp sphagnum peat moss in a resealable plastic bag. Place the bag in the crisper drawer of your refrigerator. In case you are forgetful, like me, write on the bag: “Take out and plant in June 2001”.
After you dig the bag from under your fresh lettuce and cucumbers next summer, you can plant the seeds in a warm spot outdoors. Don’t forget that it takes many years for a magnolia to grow to maturity and to flower. Even so, you’ll make a nice planting for the next inhabitants of your house.