Collards aren't just for growing in the South. They are nearly as cold resistant as kale and cabbage, but are better known as a Southern green because they can tolerate more heat.
Planting: Sow seeds 1/4 inch deep in spring, 4 weeks before the last expected frost. Space seedlings 1 foot apart in rows 3 feet apart. For a fall crop, broadcast seed 8 to 10 weeks before the first expected frost; thin to 12 inches apart.
Growing guidelines: Foliar feed with liquid seaweed extract 2 to 3 times during the growing season.
Problems: See the cabbage entry for disease and insect control measures.
Harvesting: Start picking outer leaves when plants are 1 foot tall. Frosts improve flavor.