Can kale be grown year-round in all climates?

Kale yields year-round only in zones 8-10 where winter low temps stay above 10F (-12 °C). Northern zones 3-5 experience sensitive spring-fall cycles, while southern zones escape the summer heat. I maintain year-round harvests in zone 7b with unheated greenhouses. Ultimately, the climate decides how you should plant.

Cold frames extend the growing season by four to six weeks in transitional zones. You can easily build simple cold frames out of any old window, and tilt them southward. I can keep harvesting temperatures down to -10°F (-23°C) with double-walled plastic. In milder temperatures, ventilate above 35°F (2°C) to prevent overheating. For winter, insulate the sides of the frames with straw bales during a prolonged deep freeze.

Greenhouses enable you to grow all year round in zones 3 through 7. Unheated greenhouses can protect crops at temperatures as low as 15°F (-9°C) in winter, while heated greenhouses can withstand temperatures as low as 0°F (-18°C). For passive heating, I use thermal mass barrels. For cooling, an automatic vent opener will ensure the temperature does not exceed 75°F (24°C).

Succession planting ensures a steady harvest throughout the year. Start new seeds every 3 or 4 weeks in rotating trays indoors and out (I plant in plug trays indoors in the toughest months), and combine these techniques. Your kale can be year-round!

Read the full article: When to Plant Kale: Expert Timing Guide