The Persephone Period was first named by author Elliot Coleman to describe the time of year when the days have 10 or fewer hours of light. Since most plants need at least 10 hours of daylight for active growth, plant growth pretty much stops during the Persephone Period.
According to Greek mythology, Hades, the god of the underworld, abducted Persephone, the goddess of spring, and carried her down in his chariot to the underworld to be his wife. Persephone's mother, Demeter, the goddess of agriculture and the harvest, desperately appealed to Zeus to have her daughter returned. Zeus asked if Persephone had eaten anything in Hades. Persephone admitted she had eaten four pomegranate seeds. Zeus then decreed that Persephone had to stay in Hades for four months of every year. In ancient times, farmers believed that Demeter withheld fertility and plant growth during those months, until her daughter was returned to her.
When you understand this phenomenon, you can time the planting of your winter garden to ensure success. In Gig Harbor, Washington, our Persephone Period is from November 1st through February 9th.
The secret to bountiful winter crops is to work around these dates. Since most seedlings need 60 to 90 days from planting to harvest, you can get a head start by planting pre& started fall and winter vegetable seedlings in August. The seedlings will take advantage of the daylight and warmth to reach maturity by the end of October.
The mature crops that you don't harvest will stay fresh in the ground during the cool days of winter, almost as if they were in a refrigerator that you can access when you want. However, if you plant a little later — in early October, for example — your vegetable crops will not reach maturity this year. If they are close to maturity and large enough to resist pests, they can hang out in your garden over the winter and may grow to maturity in March.