Scheduling your overwintering crops

Scheduling Guidelines for OVERWINTERED CROPS

Timing Your Planting Dates for Earliest Spring Harvest

Overwintering Basics
Welcoming the End of the Persephone Period
Welcoming the End of the Persephone Period
Here in mid Maine, the Persephone Period ends on February 6th, when day light at our latitude again reaches 10 hours in length.

Overwintering entails establishing very young plants that can survive the winter and resume growth extra early the following spring. Once day length increases to 10 hours, these plantings will grow rapidly. Keep in mind that wide fluctuations in late-winter temperatures may cause bolting before your overwintered crops reach a harvestable stage.

The most calculated approach to scheduling seeding for overwintered crops involves seeding in the late fall, so that germination and the first stages of growth occur before the plant goes dormant during the Persephone period. Growth will begin again when days begin to lengthen.

Another overwintering method involves sowing just before the ground freezes, so that germination occurs after deep winter, as day length increases and temperatures warm. This method can result in a lot of dead seed if conditions do not pan out. (There is a risk that a higher percentage of seeds will rot in the soil during cold, wet conditions.)

An additional strategy is to seed just as the ground begins to thaw, or just as the Persephone period is ending (so technically, it is not overwintering); only the top inch or two of soil needs to be thawed in order to plant the seed.

Scheduling Guidelines for Planting the Winter-Harvest High Tunnel

Ten hours of daylight

Overwintering Planting Chart
Use our clickable Overwintering Planting Chart as a guide, staggering your plantings by the week for successive earliest-spring harvests.

Use our clickable Overwintering Planting Chart to time your planting dates for earliest spring harvest.

Keep in mind that the planting dates are back-scheduled from the last 10-hour day at your latitude.

The number of weeks before the Persephone period is calculated for each listed crop.

The crops are grouped, as outlined in the chart key, to reflect their reliability for overwintering success.