Bath Island Cos (Romaine) Lettuce

Latuca sativa

Approximately ~ 200 seeds per packet

Germination 95%  Packed for 2025

Bath Island Cos Lettuce is a variety of Romaine lettuce, known for its long, sturdy leaves and crisp texture. The leaves are a rich green color and grow upright, forming dense, tightly packed heads. This variety has a slightly sweet, mild flavor and is often prized for its crunch, making it an ideal choice for salads and sandwiches. The leaves tend to be more robust than other Romaine varieties, and Bath Island Cos Lettuce has a strong resistance to bolting, which makes it reliable for longer growing seasons. It's also fairly heat-tolerant compared to some other types of lettuce.

Origins and History

Bath Island Cos is a traditional romaine-type lettuce with roots tracing back to 18th and 19th century England, where it was widely cultivated in the Bath region. “Cos” refers to the island of Kos in Greece, believed to be the origin point of romaine lettuces brought westward through Mediterranean trade. Bath Island Cos became popular for its crisp texture and elegant form, earning a place in Victorian kitchen gardens and market stalls. Today, it is treasured as an heirloom variety for its historical significance and reliable performance.

Appearance and Characteristics

Bath Island Cos is an upright romaine lettuce that forms elongated, narrow heads of tightly packed leaves. The outer leaves are dark green, slightly savoyed, and crisp, while the inner hearts are pale, tender, and sweet. Plants typically grow 10–12 inches tall with a firm, compact structure that resists bolting better than many other heirloom lettuces. Its crisp rib and balanced flavor make it one of the finest traditional cos lettuces.

Culinary Uses

Highly versatile in the kitchen, Bath Island Cos shines in salads, particularly the classic Caesar salad, where its crunch and sweetness are unmatched. It is also suitable for grilling or braising, where the firm leaves hold up to heat. The pale inner leaves can be used as edible “cups” for fillings, while the darker outer leaves are excellent for wraps, sandwiches, and juicing.

Growing Tips

This heirloom thrives in cool weather and is best suited for spring and fall plantings. It can be grown successfully in USDA Zones 4–9. Sow seeds directly outdoors ¼ inch deep in fertile, well-drained soil, spacing plants 8–10 inches apart in rows 12–18 inches apart. For succession planting, sow every 2–3 weeks to extend the harvest season. Bath Island Cos prefers full sun but benefits from partial shade in warmer regions to delay bolting. Consistent watering ensures crisp, tender leaves.

Harvesting Guidance

Bath Island Cos can be harvested at different stages: as “cut-and-come-again” baby greens about 30 days after sowing, or as full heads at 65–70 days. To harvest whole heads, cut at the base just above soil level when leaves are full and tight but before the plant begins to bolt. For extended use, outer leaves can also be picked individually, allowing the plant to continue producing. Properly cooled and stored, the harvested heads retain their crispness for several days.