VegetableLettuce
Dark Green Cos Lettuce
Dark Green Cos Lettuce is a crisp, open-pollinated romaine that delivers the sweet, mild flavor Caesar salad lovers crave. Its long, narrow dark green leaves stay tender even as they mature, reaching full harvest in just 50-55 days. Hardy across zones 2-10 and compact enough for containers, this variety thrives in cool seasons and rewards gardeners with consistent, reliable crops spring and fall.
Photo © True Leaf Market
Growing Conditions
USDA Zone
2-10
Sunlight
Full Sun
Soil
Well-drained, Fertile Loam With Consistent Moisture
Growth Stats
10 in
Height
TypeUpright
Spacing
8
Plant Profile
Sunlight
Full Sun
Water
—
Zones
2-10
Size
10in H x ?in W
Growth
—
Care
High
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Highlights
The leaves are exceptionally crisp with a naturally sweet, mild character that shines in Caesar salads and other fresh preparations. Dark Green Cos grows upright and compact, reaching 5-10 inches tall with just 8 inches of spacing needed between plants, making it efficient for small gardens and container growing. Its dark green color deepens as it matures, and the narrow leaf structure gives it a distinctly elegant appearance on the plate.
Common Uses
This lettuce was bred specifically for Caesar salads, where its crisp texture and mild sweetness shine. The long, narrow leaves are ideal for the classic preparation, holding dressing beautifully while maintaining their snap. Home gardeners also use it in mixed green salads and as a fresh wrapping for other ingredients, though its true home is on the classic Caesar plate.
Growing Timeline
No timeline data available yet for this variety.
Care Instructions
Direct Sow
Sow Dark Green Cos seeds directly in the garden in spring and fall. Plant at the optimal time for cool-season growth, avoiding the hot summer period. Space seeds 8 inches apart in rows 18 inches apart.
Harvesting
Dark Green Cos reaches harvest readiness in 50-55 days from sowing. Pick individual outer leaves once they reach usable size, or harvest the entire head by cutting at the base when it feels firm and crisp to the touch. The timing matters: harvest in cool morning hours for maximum crispness, and gather before the plant bolts in heat. The heads typically reach their sweetest flavor when harvested before temperatures rise above 70°F.
Growing Calendar
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Companion Planting
Pests & Diseases
Ecology & Traits
Edible
Scientific Classification
Lactuca sativa
Family
Asteraceae
Genus
Lactuca
Growth Habit
Upright
Native Status
L48 (I)PR (I)VI (I)CAN (W)