How to Grow Parris Island Cos
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Parris Island Cos
Lactuca sativa var. longifolia
vegetableParris Island Cos is a crisp, upright romaine lettuce variety known for its elongated, deep green leaves and excellent flavor. It forms tight, self-blanching heads that are ideal for salads and has been a popular heirloom variety since the 1950s. This lettuce is heat-tolerant compared to many other romaine varieties, making it a reliable choice for spring and fall gardens.
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Example Parris Island Cos timeline · Pittsburgh, PA (Zone 6b)
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Plant Parris Island Cos
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Parris Island Cos
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Parris Island Cos dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-10; best in cooler seasons (spring and fall) but heat-tolerant for a romaine variety
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Get my Parris Island Cos timeline →Growth Stages
Seedling
7-14 daysTiny seed leaves (cotyledons) emerge, followed by the first true leaves. Plants are fragile and light green.
Keep soil moist but not soggy; provide bright light; maintain 60-65°F for best germination. Thin seedlings once first true leaves appear.
Vegetative Growth
20-30 daysPlant develops multiple true leaves and grows in rosette formation. Leaves are increasingly crinkled and deeply lobed, expanding outward.
Maintain consistent moisture; provide full sun; thin to final spacing once plants have 2-3 true leaves. Side-dress with compost if needed.
Head Formation
15-25 daysLeaves begin curling inward and upward, forming a loose to tight, elongated head structure. Plant reaches near-full size with dense, deep green foliage.
Continue consistent watering; ensure adequate spacing to promote air circulation. Watch for bolting signs (flower stalk emergence) in warm weather.
Maturity
5-10 daysHead is fully formed, compact, and crisp with excellent texture. Leaves show deep green color and tight structure typical of the variety.
Maintain cool temperatures and consistent moisture to prevent bolting. Monitor for pests and diseases. Ready to harvest.
Senescence/Bolting
Varies with temperatureFlower stalk begins to elongate from center of head; leaves become bitter and texture becomes tougher. Plant transitions to reproductive stage.
Harvest immediately before bolting becomes advanced. In hot weather, use shade cloth to extend harvest window. Discard bolted plants or deadhead for secondary leaf production.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with water to dislodge; use insecticidal soap; introduce ladybugs or lacewings; neem oil as last resort
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and
Handpick in early morning; use beer traps; apply diatomaceous earth around base; copper tape barriers
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Yellow sticky traps; strong water spray; insecticidal soap; neem oil; encourage beneficial parasitic wasps
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Plant resistant varieties; control aphids; remove and destroy infected plants; use reflective mulch to confuse vectors
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Improve air circulation; avoid overhead watering; apply sulfur dust at first sign; plant resistant varieties; remove affected leaves
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Fence garden with 2-3 foot hardware cloth; use chicken wire; apply cayenne pepper repellent; motion-activated sprinklers
Uses
Fresh salads and wraps
CulinaryThe crisp, tender leaves of Parris Island Cos are ideal for Caesar salads, garden salads, and lettuce wraps. The robust leaf structure holds dressings well and provides excellent crunch and texture. [source]
Cooked greens
CulinaryWhile primarily used fresh, Parris Island Cos can be lightly sautéed or added to soups and stir-fries. The mild flavor and tender texture make it suitable for gentle cooking methods. [source]
Juicing and smoothies
HouseholdThe leaves can be added to fresh vegetable juices and green smoothies for nutritional boost. The mild taste blends well with fruits and other vegetables. [source]
Nutritional benefits
MedicinalRich in vitamins A, K, and C, as well as folate and fiber. Contains beneficial compounds with mild antioxidant properties that support digestive health. [source]
Pollinator support
WildlifeIf allowed to bolt and flower, the yellow flowers attract beneficial insects including bees, hoverflies, and other pollinators to the garden. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Harvest when heads are firm and crisp but before bolting begins (before flower stalk emerges). Cut entire head 1-2 inches above soil line in early morning when leaves are turgid and cool. For continuous harvest, pick outer leaves once head is formed, or cut entire head. In hot weather, harvest in early morning or late evening. Store in refrigerator crisper drawer for up to 2 weeks.
Fun Facts
- 🌱 Parris Island Cos was named after Parris Island, South Carolina, where it was selected and developed as a superior heat-tolerant romaine variety in the 1950s.
- 🌱 This variety is notably self-blanching, meaning the inner leaves naturally lighten and become tender through the plant's own growth pattern, without requiring special wrapping or shading techniques.
- 🌱 Romaine lettuce, including Parris Island Cos, is the traditional choice for classic Caesar salad and was popularized in the United States when the Caesar salad was invented in the 1920s in California.
Gardening Terms
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