Planting

Iceberg Lettuce

Planting Time Lettuce is as cool as a cucumber, and Iceberg Lettuce is no different. Plant it early in the spring or in the fall. Once the weather gets hotter than a picnic blanket in July, the plant will bolt, turning bitter faster than spoiled milk.

Depth & Spacing Plant seeds one-quarter inch deep. Thin the seedlings to 10 to 12 inches apart. Give the head room to grow big and round. Rows should be 18 inches apart.

Soil & Fertilization Iceberg Lettuce likes rich, loose, well-drained soil with a heap of compost mixed in. Feed them with a nitrogen-rich fertilizer early on to encourage big, green leaves.

Watering Needs Water steadily and consistently. Keep the soil evenly moist like a damp sponge. Water at the base and keep the leaves dry. Inconsistent watering makes the lettuce taste bitter.

Sunlight Requirements Full sun is best in early spring or fall. Give it 6 hours minimum. In warmer climates, afternoon shade is appreciated to keep the plant from bolting.

Harvesting Harvest when the heads are firm and heavy to the touch. Press lightly on the top; if it feels hard, it’s ready. Cut the head off at the base with a sharp knife.

Troubleshooting Watch out for aphids, slugs, and bolting. Keep soil cool with mulch and water consistently to prevent bitterness and premature bolting.

Captain Greenhouse Tip Iceberg Lettuce needs lots of airflow in the greenhouse. Keep the temperatures cool, and if you see it stretching tall, drop the temperature or give it more shade.