Planting leafy greens is exceptionally easy and for many variety results in both an ongoing harvest, as well as the opportunity for a second harvest in the same season. Some of the hardier varieties can be effectively overwintered, as well.
Timing will very much depend on what variety you’re planting. For instance, lettuces for the most part will do well in warm weather, so they’re a good choice to plant in the spring for harvest over the summer months and into the fall.
Summer’s leafy green harvest
For cabbage, mustard greens and collard greens, plant seeds three or four weeks before the last frost date in your area or when daytime temperatures will reliably reach into the 50s. For more heat-loving plants, germinate the seeds indoors starting in early spring and plant in late spring for a summer harvest.
Fall’s leafy green harvest
Plant a second cabbage crop in late summer for harvest in the fall, and focus on short-season varieties to ensure they’ll mature before the first frost arrives. Cabbages, kale, mustard greens and collard greens will all survive a mild frost, and the kick of cold actually cuts some of the bitterness in mustard and collard greens.
Winter & Early Spring’s leafy green harvest
If your zone is free of frosts through the winter, you can still easily grow and harvest most varieties of greens through the winter months. Make sure to wait until daytime temperatures have dropped below 75 degrees before you plant. If you’re overwintering plants, make sure to use a cold frame or other form of insulation like a polytunnel or burlap shield.
Also, consider using succession planting to ensure an ongoing harvest of greens without being buried by too many all at once. To do this, plant small patches of 2 to 4 feet every two weeks throughout the growing season.
Whatever time you’re considering planting, you’ll get the best results if you can count on eight hours of sunshine a day.