Collard greens are a hardy member of the Brassica oleracea species, which also includes cabbage and kale. This leafy green is a staple in many home gardens because it grows vigorously and thrives in cooler weather. Unlike many garden crops, the collard harvest period is long, extending across the growing season. Knowing the optimal time to pick the leaves ensures the best tenderness and depth of flavor.
Signs Collard Greens Are Ready
The primary signal that collard greens are ready for harvest is reaching a usable size, typically 60 to 80 days after planting from seed. Look for leaves that are a vibrant, dark green color and feel firm to the touch. The most tender leaves usually measure around 8 to 10 inches in length.
Harvesting can begin once the plant is well-established, long before it reaches full maturity. While larger, older leaves can be picked, they tend to be tougher and may develop a bitter taste. Removing leaves regularly directs the plant’s energy into producing new, tender growth, keeping the plant productive and delaying bitterness.
How Temperature Affects Harvest Timing
Temperature plays a significant role in the flavor profile of collard greens. They are naturally cool-season crops, and their taste improves with exposure to cold. When temperatures drop, especially after a light frost, the plant converts stored starches into simpler sugars.
This process, called “frost sweetening,” results in a noticeably sweeter and less bitter leaf. Many gardeners wait until the first autumn chill for their main harvest. Conversely, prolonged periods of summer heat can stress the plants, causing them to bolt (go to seed) prematurely. Bolting diverts energy from leaf production and increases bitterness, signaling an immediate harvest is necessary.
Proper Harvesting Techniques
You can choose between two main methods for picking collard greens, depending on your desired yield. The most common approach is the “cut-and-come-again” technique, which allows for continuous production. This method involves removing only the outer, larger leaves from the plant.
To execute this, use a sharp knife or shears to cut the leaf stem close to the main stalk. It is important to leave the inner, smaller leaves—the growing crown—intact so the plant can continue to photosynthesize and produce new foliage. Ensure at least four to six leaves remain on the plant to maintain its health.
The alternative is to harvest the entire plant at once, which is best done when the plant is young for maximum tenderness. In this case, cut the main stem about four inches above the ground, which may encourage a second, smaller flush of leaves to emerge.
Immediate Post-Picking Care
Once collard leaves are picked, they require immediate attention to maintain freshness and flavor. The first step is to wash the leaves thoroughly in cold water to remove any soil, grit, or small pests. Multiple rinses may be necessary to ensure all fine particles are removed from the crinkled leaf surfaces.
After washing, gently pat or spin the leaves dry, as excess moisture accelerates spoilage. For short-term storage, place the collards in the refrigerator’s crisper drawer. Wrapping them loosely in a damp paper towel and then placing them in a perforated plastic bag helps maintain high humidity and air circulation, keeping the leaves crisp. They are best used within a few days to a week for the highest quality taste and texture.