Annuals

Lactuca sativa 'Great Lakes'

Great Lakes Lettuce

UnknownMediterranean

At a Glance

Typeannual
Habitcompact rosette
Foliagedeciduous
Height8-12 inches
Width12-16 inches

Overview

Lactuca sativa 'Great Lakes' is a premium iceberg lettuce cultivar that produces exceptionally large, dense heads with crisp, tightly packed leaves. This cool-season annual forms compact rosettes of bright green outer leaves that gradually transition to pale green or nearly white inner leaves as they approach the center of the head. The leaves are broad and rounded, measuring 6-8 inches in length, with slightly ruffled margins and a smooth, glossy surface texture. The distinctive feature of Lactuca sativa 'Great Lakes' is its ability to form remarkably dense heads that can reach 8-10 inches in diameter when fully mature. Each leaf displays prominent white midribs that contribute to the characteristic crisp, crunchy texture that makes this cultivar highly prized for fresh consumption. The plant develops a shallow taproot system with numerous fibrous lateral roots that efficiently absorb moisture and nutrients from the upper soil layers. What sets Lactuca sativa 'Great Lakes' apart from other iceberg lettuce varieties is its superior heat tolerance and slower tendency to bolt, making it more reliable in variable weather conditions. When allowed to go to seed, the plant will eventually produce a tall flowering stalk bearing small, pale yellow composite flowers typical of the Asteraceae family, though commercial cultivation focuses on harvesting the heads before this reproductive stage.

Native Range

Lactuca sativa originates from the Mediterranean basin and western Asia, where wild forms of lettuce can still be found growing naturally on rocky slopes, disturbed soils, and along roadsides. The cultivar 'Great Lakes' was developed through selective breeding programs in North America during the mid-20th century, specifically bred to improve upon existing iceberg lettuce varieties.

Suggested Uses

kitchen gardens, container growing, market gardening, salad production, cool-season crop rotation

How to Identify

Lactuca sativa 'Great Lakes' can be readily identified by its characteristic formation of tight, dense heads composed of crisp lettuce leaves with bright green outer foliage that gradually fades to pale green or white toward the center. The leaves feature prominent white midribs and maintain a distinctly crunchy texture when fresh and properly grown. Unlike loose-leaf varieties or romaine lettuces, this cultivar forms compact, cabbage-like heads that feel solid and heavy when mature. The 'Great Lakes' variety is distinguished from other iceberg types by its particularly large head size, often reaching 8-10 inches in diameter, and its notable heat tolerance that allows it to maintain quality longer in warm conditions without bolting prematurely.

Appearance

Bloom Information

summer (if allowed to bolt)

Detailed Descriptions

Flower Description

pale yellow

Foliage Description

bright green outer leaves fading to pale green or white centers

Growing Conditions

Sun Requirements

full sun to partial shade

Soil pH

6.0-7.0

Water & Climate

Water Needs

moderate to high

Time to Maturity

75-90 days

Care & Maintenance

Care Guide

Lactuca sativa 'Great Lakes' requires consistent moisture and cool growing conditions for optimal head development and quality. Maintain evenly moist soil by providing approximately 1-1.5 inches of water per week through deep, infrequent watering sessions rather than frequent shallow watering. Apply a balanced fertilizer at planting time and side-dress with nitrogen fertilizer 3-4 weeks after transplanting to promote vigorous leaf growth and proper head formation. Mulch around plants with organic material to retain soil moisture, suppress weeds, and keep the root zone cool during warm weather. Monitor plants regularly for signs of heat stress and provide afternoon shade in hot climates to prevent premature bolting and maintain leaf quality.

Pruning

Lactuca sativa 'Great Lakes' requires minimal pruning during its active growing period. Remove any damaged, yellowing, or diseased outer leaves as needed to maintain overall plant health and prevent pest issues. Harvest the entire head when it feels firm and well-developed, typically 75-90 days after planting, by cutting at the base with a sharp, clean knife and leaving the root system intact in the soil. If flower stalks begin to emerge from the center of the plant, remove them immediately to prevent bolting and maintain the quality and crispness of the leaves for as long as possible.

⚠️ Toxicity Warning

Lactuca sativa 'Great Lakes' is completely non-toxic and safe for human consumption at all stages of growth. All parts of the plant are edible, though the crisp leaves are the primary portion consumed. The plant is also safe for pets when consumed in normal quantities, although very large amounts may cause mild digestive upset in some animals due to the high fiber content.

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

Days to Maturity

75–90 days

Plant Spacing

12 inches

Companion Planting

Good Companions

carrots
radishes
onions
chives
marigolds
nasturtiums

Avoid Planting With

fennel
broccoli
sunflowers