Lactuca sativa 'Parris Island Cos'

Parris Island Cos Lettuce

Open-pollinated cultivar (1952 AAS winner from USDA Vegetable Breeding Lab, Charleston, SC; named for nearby Parris Island); the species L. sativa is native to the Mediterranean region

At a Glance

TypeAnnual
HabitUpright
FoliageDeciduous
Height10-12 inches (25-30 cm)
Width6-8 inches (15-20 cm)
Maturity1 years

Growing Zones

USDA Hardiness Zones

3 - 9
These zones indicate the coldest temperatures this plant can typically survive.
What's my zone? →
Frost Tolerancehardy

Key Features

Maintenancelow

Overview

Lactuca sativa 'Parris Island Cos' is a romaine (cos-type) annual lettuce in the family Asteraceae forming an upright elongated head 10-12 inches (25-30 cm) tall and 6-8 inches (15-20 cm) wide. The cultivar produces dark green thick crisp outer leaves with prominent white midribs and lighter green hearts. Open-pollinated and an All-America Selections winner in 1952. Developed at the USDA Vegetable Breeding Lab in Charleston, South Carolina, and named for nearby Parris Island. Seeds can be saved. Romaine type produces an upright elongated head with thick crisp-ribbed leaves. Mosaic virus tolerant. The cultivar has served as a benchmark romaine in the seed trade since its 1952 release and remains widely grown for home and commercial production. Bolts in sustained heat above 80°F (27°C), the primary growing limitation. Maturity is 75-85 days from seed for a mature head, 30-35 days for baby leaf. Succession-sown every 2-3 weeks. Slugs and aphids are the primary pests. Not deer-resistant. Non-toxic edible crop. Annual with moderate growth rate.

Native Range

Lactuca sativa 'Parris Island Cos' is an open-pollinated cultivar; an All-America Selections winner in 1952. Developed at the USDA Vegetable Breeding Lab in Charleston, South Carolina, and named for nearby Parris Island. The species L. sativa is native to the Mediterranean region.

Suggested Uses

Grown in vegetable gardens, raised beds, and containers of at least 2 gallons (8 L) for culinary use: Caesar salads, sandwich layering, wraps, and grilling. Romaine lettuce with thick crisp ribs and dark green leaves. 1952 USDA Charleston release named for Parris Island. Mosaic virus tolerant. Open-pollinated and suitable for seed saving. Succession-sown for continuous harvest. Non-toxic. Not deer-resistant. Annual. Not suited to warm summer climates without afternoon shade.

How to Identify

Identified by an upright elongated romaine head with dark green thick crisp leaves, prominent white midribs, and lighter green hearts. Separated from butterhead types (loose soft round) and crisphead types (tight firm round) by the upright elongated form with thick crisp ribs. In family Asteraceae.

Appearance

Size & Dimensions

Height10" - 1'
Width/Spread6" - 8"

Reaches mature size in approximately 1 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bolts in sustained heat. Small yellow composite flowers (daisy family) on bolting stalks. Bolting makes leaves bitter and plants are pulled when the bolting stalk appears.

Detailed Descriptions

Flower Description

Small yellow; daisy-family composite; on bolting stalks only

Foliage Description

Dark green outer leaves with prominent white midribs; lighter green hearts; thick crisp ribs; deciduous

Growing Conditions

Sun Requirements

Requires 4-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.0(Neutral)
357912
Soil Types
Drainagemoist

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

75-85 days from seed to mature head; 30-35 days for baby leaf

Care & Maintenance

Care Guide

Full sun to partial shade. Rich moist soil at pH 6.0-7.0. Cool-season crop; bolts above 80°F (27°C). Mosaic virus tolerant. Succession-sown every 2-3 weeks. Open-pollinated and seeds can be saved (AAS 1952). Slugs and aphids are the primary pests. Not deer-resistant. Non-toxic. Annual.

Pruning

Harvest takes the entire head by cutting at the base, or harvests outer leaves through cut-and-come-again. Plants are pulled when the bolting stalk appears. Succession-sown.

Maintenance Level

low

Container Growing

✓ Suitable for container growing

Minimum container size: 2 gallons

⚠️ Toxicity Warning

Non-toxic

Planting Guide

Planting Methods & Timing

Planting Method

both

Indoor Start

4 weeks before last frost

Direct Sow Timing

Early spring 2-4 weeks before last frost; again in late summer for fall harvest

Days to Maturity

75–85 days

Plant Spacing

8 inches

Companion Planting