Iceberg Lettuce

150 Seeds

Iceberg lettuce is a crisp, cool-season lettuce that forms dense, round, pale-green heads. In the Gulf, it should be grown during the cooler months, because temperatures that are too high can cause bolting, loose heads, bitter flavor, and poor head formation.

Best Planting Time

• October to January — best period for most Gulf areas.
• In cooler Gulf locations, sowing can continue into February.
• For the best head formation, aim to grow it when daytime temperatures are approximately 15–24°C.
• Avoid sowing during the hot months.

Seed Preparation

• Do not soak the seeds.
• Lettuce seeds are very small and need light to germinate.
• Use fresh, high-quality seeds.

Soil Preparation

Iceberg lettuce prefers fertile, loose, moisture-retentive soil with good drainage.

Recommended mix:

• 40% Sandy loam soil
• 30% Well-rotted compost
• 20% Coco peat
• 10% Perlite

Ideal soil pH:

• 6.0–7.0

Sowing Method

• Sow seeds in seed trays or directly into prepared beds.
• Plant only 0.3–0.5 cm deep.
• Cover with a very thin layer of fine soil.
• Keep the surface consistently moist until germination.
• Transplant when seedlings have 3–4 true leaves, usually after about 3–4 weeks.

Temperature & Light

• Ideal germination temperature: 15–21°C
• Ideal growing temperature: 15–24°C
• Provide 5–7 hours of sunlight.
• In the Gulf, give light afternoon shade if the weather becomes warmer than 25–28°C.
• Avoid excessive heat around the root zone.

Watering

• Keep the soil consistently moist but never waterlogged.
• Water when the upper 1–2 cm begins to dry.
• During warm Gulf weather, check containers daily.
• Morning watering is recommended.
• Inconsistent watering can result in small heads and leaf-tip burn.

Germination Time

• 4–10 days

Plant Spacing

• 30–35 cm between plants.
• 35–45 cm between rows.

Good spacing is particularly important for Iceberg lettuce because the plants need room to develop compact heads.

Harvest

• Harvest approximately 70–90 days after sowing, depending on temperature and growing conditions.
• Cut the head when it feels firm and well-filled.
• Harvest early if temperatures begin rising to prevent bolting.
• Harvest in the early morning for crisp, hydrated heads.

Fertilization

• Add compost before planting.
• Apply a balanced vegetable fertilizer approximately 2–3 weeks after transplanting.
• Feed lightly every 2–3 weeks while plants are actively growing.
• Avoid excessive nitrogen, which can produce soft, overly leafy plants.

Gulf Climate Tips

• Cool weather is the key to success.
• Use 30–40% shade cloth during unexpectedly warm periods.
• Mulch around plants to keep the root zone cooler and reduce evaporation.
• Avoid letting plants become heat-stressed.
• Provide good air circulation to reduce fungal problems.
• Watch for aphids, whiteflies, thrips, slugs/snails, and caterpillars.
• If the plant starts sending up a tall central flower stalk, it is bolting; harvest immediately.