While leafy greens are always available, like most plants, they too have their peak season. Collards, kale, turnip greens, and mustard greens are at their best from October through early spring. Swiss chard beet greens are best from the spring through fall. Dandelion greens, a popular remedy for the liver, are available and best in the spring and summer. Leafy greens run the gamut of flavors.
Young plants have small, tender leaves and a mild flavor.
Mature plants have tougher leaves and stronger flavors. If it's mild you are looking for, try collards, chard, bok choy, or spinach. Kale, a very hearty plant with curly, course leaves, is slightly stronger in flavor collard greens. The colored varieties of kale known as salad savoy are typically used as decorative garnish, but are just as edible as the more common variety. When shopping, always look for crisp leaves with a fresh green color.