What are the sun requirements for Lactuca sativa 'Iceberg'?

Lactuca sativa 'Iceberg' requires full sun to partial shade.

How much water does Lactuca sativa 'Iceberg' need?

Lactuca sativa 'Iceberg' has consistent moisture water needs.

Vegetables

Lactuca sativa 'Iceberg'

Iceberg Lettuce

Asteraceae Mediterranean

At a Glance

TypeVegetable

Habitcompact, head-forming

Foliagedeciduous

Height8-12 inches

Width10-14 inches

Overview

Lactuca sativa 'Iceberg' is a cool-season annual vegetable renowned for its tightly packed, crisp head of pale green leaves. This cultivar forms dense, round to slightly flattened heads that can reach 6-8 inches in diameter when mature. The outer leaves are light to medium green, while the inner leaves are nearly white to very pale green due to blanching from being tightly wrapped within the head. The leaves of Lactuca sativa 'Iceberg' are thick, succulent, and notably crisp with prominent white midribs. Individual leaves are broadly oval with smooth or slightly ruffled margins and a cupped shape that contributes to the tight head formation. When cut, the leaves produce a milky white latex, characteristic of the Lactuca genus. The plant produces small, inconspicuous yellow flowers on tall, branching stems if allowed to bolt, though commercial cultivation focuses on harvesting before flowering occurs.

Native Range

Lactuca sativa is believed to have originated in the Mediterranean region and western Asia, likely derived from wild lettuce species native to this area. The cultivar 'Iceberg' was developed in the United States in the late 19th century through selective breeding programs focused on creating a lettuce with exceptional crispness and shipping durability.

Suggested Uses

salads, sandwiches, wraps, garnish, fresh eating

How to Identify

Lactuca sativa 'Iceberg' can be identified by its distinctive tight, round heads of pale green to white leaves with exceptional crispness. The outer wrapper leaves are medium green and loosely arranged, while the inner leaves form a dense, blanched core. Key identifying features include the thick, crunchy leaf texture, prominent white midribs, and the characteristic milky sap that appears when leaves are broken or cut. The heads feel solid and heavy when properly mature, distinguishing it from looser leaf lettuce varieties.

Appearance

Bloom Information

summer, if allowed to bolt

Detailed Descriptions

Foliage Description

pale green to white inner leaves, medium green outer leaves

Growing Conditions

Sun Requirements

full sun to partial shade

Soil pH

6.0-7.0

Water & Climate

Water Needs

consistent moisture

Frost Tolerance

hardy

Time to Maturity

70-90 days

Care & Maintenance

Care Guide

Lactuca sativa 'Iceberg' requires consistent moisture throughout the growing season, with soil that remains evenly moist but not waterlogged. Water deeply at the base of plants to avoid wetting the leaves, which can promote disease. Apply a balanced fertilizer at planting and side-dress with nitrogen fertilizer 3-4 weeks after transplanting. Maintain soil temperatures between 60-65°F for optimal growth and prevent premature bolting. Mulch around plants to retain moisture, suppress weeds, and keep soil cool during warm weather.

Pruning

Lactuca sativa 'Iceberg' requires minimal pruning during growth. Remove any damaged or yellowing outer leaves to maintain plant health and improve air circulation around the developing head. Harvest the entire head by cutting at the base when it feels firm and solid, typically 70-90 days after planting. If outer leaves become tough or bitter due to heat stress, they can be removed to encourage continued growth of the tender inner head.

⚠️ Toxicity Warning

Lactuca sativa 'Iceberg' is non-toxic and safe for human consumption. All parts of the plant are edible, though the leaves are the primary consumed portion. The milky latex produced when leaves are cut is harmless and naturally occurring. This lettuce is safe for pets in small quantities, though large amounts may cause digestive upset.