Dark Green Cos, Heirloom Romaine Lettuce Seeds

Dark Green Cos, Heirloom Romaine Lettuce Seeds — The Classic Patio Romaine With Tall, Crisp, Dark Green Heads

Dark Green Cos (Lactuca sativa) is the definitive heirloom romaine — tall, upright heads with deep green outer leaves and a crisp, pale, sweet inner heart that has made it the backbone of Caesar salads for generations. Heads grow 10–12 inches tall with substantial, well-blanched centers. Excellent flavor and texture, heat-tolerant for a romaine, and well-suited to patio gardens, containers, and raised beds. Harvest as a full head or pick outer leaves cut-and-come-again style for a continuous supply through the season.

Why Grow Dark Green Cos?

• Tall, upright 10–12 inch heads — classic romaine form with deep green outer leaves
• Crisp, pale, sweet inner heart — the gold standard for Caesar salads and wraps
• Cut-and-come-again or full head harvest — flexible harvest method for continuous production
• Ideal for patio gardens and containers — compact footprint, big yield
• Cool-season reliable — excellent spring and fall performer
• Open-pollinated heirloom — save seed year after year

Growing Notes

Direct sow outdoors in early spring (4–6 weeks before last frost) or in late summer for a fall crop. Or start indoors 4–6 weeks before last frost and transplant out. Sow seeds ¼ inch deep. Thin or transplant to 8–10 inches apart in rows 12–18 inches apart. Prefers cool weather — flavor and texture peak below 75°F. Water consistently and evenly. Harvest full heads when firm and 10–12 inches tall, or harvest outer leaves regularly for cut-and-come-again production.

Packed and shipped by Box Garden Seeds LLC — heirloom seeds grown without GMOs, selected for flavor, resilience, and your garden's success.