Collard greens generally take about 75 days to reach maturity, but you can start harvesting the leaves before they are fully mature. You can harvest collard greens by cutting the plant down to ground level when it reaches about 6 to 10 inches in height or by picking individual leaves based on your size preference. The leaves taste better after the plants have been exposed to a few frosts, which enhances their sweetness. Collards can tolerate cold temperatures into the upper 20s Fahrenheit. For best taste, harvest the young, dark green leaves up to 10 inches long. You can pick the lower leaves first, working your way up the plant, and even harvest leaves throughout the summer, fall, and winter if growing conditions allow. Collards are a cool-weather crop, so they are often planted for fall and winter harvests in warmer southern climates or spring and fall in cooler areas. In summary:

• Collards take about 75 days to mature.
• Harvest leaves when they are 6 to 10 inches tall or individual leaves up to 10 inches long.
• Best flavor comes after exposure to frost.
• You can harvest leaves throughout the growing season, picking lower leaves first.
• Plant in spring or fall depending on your climate for optimal harvest time.