Lactuca sativa var. capitata 'Iceberg'
Iceberg lettuce
Common names: Iceberg salad, Crack lettuce
At a glance
- Light
- Full sun
- Spacing
- 35 cm, rows 35 cm
- Lifespan
- Annual
- Sowing
- Mar–Jul
- Harvest
- Jun–Oct
- Hardiness
- Cold damage below −3 °C
- Water need
- High
- For children
- Well suited
Photo: CostaPPPR · CC BY-SA 4.0 · Source
This description was machine-translated.
Description
The Iceberg lettuce forms a firm, spherical head of crisp, pale green leaves and epitomizes freshness and bite. It is heat‑tolerant and stores longer than loose‑leaf lettuce, retaining its characteristic crunch in the refrigerator for days.
Care instructions
Plant seedlings in nutrient‑rich soil and water generously and evenly, Iceberg lettuce requires ample moisture for firm heads, especially during head formation. Keep sufficient spacing so heads can fully develop, and harvest when they feel firm before they bolt. A mulch layer keeps the soil cool and moist.
The care notes were machine-translated from German.
Garden year
SowingMar–Jul
HarvestJun–Oct
Germination
- Soil temperature
- from 5 °C, ideally 18 °C
- Days to sprout
- 4 to 10 days
- Light
- Needs light to sprout
- Sowing depth
- Press in, don't cover
- How to start
- Start indoors, then plant out
Soil & site
Soil pH
Soil type
loamy, humus-rich, well-drained, nutrient-rich
Iceberg lettuce wants deep, humus-rich, free-draining soil; loamy sand or sandy loam with a loose, crumbly structure is ideal. Keep the soil evenly moist but without waterlogging, and improve heavy clay soils with mature compost before planting; you should avoid a pH below 6.
Lettuce and other members of the daisy family are light to moderate feeders. A break of about 3 years is enough, and they are well suited as gap fillers between the main crops.
Feeding
Medium feeder
Months
Mar, Apr, May, Aug, Sep
When preparing the bed in spring, work in mature compost shallowly; this covers the basic needs of the spring and early summer crop. For the autumn crop, fold compost in before planting in late summer too, and on lean soils add some horn shavings for slow nitrogen release. During head formation, no further feeding is needed: too much nitrogen makes the heads loose and raises the nitrate content.
Overwintering
Iceberg lettuce is an annual and dies at the first hard frost. You do not need to overwinter it; simply sow anew next spring. You can protect a late batch in autumn from light frosts with horticultural fleece or in a cold frame; otherwise plant outdoors after the Ice Saints (mid-May).
Propagation
Methods
- From seed
Iceberg lettuce is propagated only by sowing. You can begin starting it on the windowsill or in the greenhouse from the beginning of February/March: sow the seeds thinly in seed trays, cover them only very lightly (iceberg lettuce is a light germinator, at most 0.5 cm of soil) and keep the soil evenly moist at 10 to 16 °C. At this temperature the seedlings germinate in about 7 to 10 days. Thin them out as soon as the first true leaf shows. From mid-May, when frosts no longer threaten, plant the young plants outdoors at 30 to 35 cm spacing. Do not set the root ball too deep; the root collar should stay just above the soil, otherwise the plant rots. Alternatively, direct sowing outdoors is possible from mid-April: draw seed drills 30 cm apart, sow thinly (0.5 to 1 cm deep) and later thin to 30 to 35 cm. Since iceberg lettuce shows germination inhibition from about 20 °C, in high summer it is worth starting it indoors in a shady, cool place. For a staggered harvest, sow again every 3 to 4 weeks. Vegetative propagation (division, cuttings, offsets) is not possible; iceberg lettuce is annual and forms seed after bolting. With F1 hybrid varieties, saving your own seed is possible, but the offspring do not come true to type.
Companion planting
Good neighbors
carrot family (Apiaceae)
Calendula and Tagetes next to carrots keep the carrot fly away with their scent.
For example Florence fennelCorianderCelery (Stalk Celery)CarawayFennelparsley root and 17 more species in the catalogue
Source: classic companion planting (DACH-Gartenpraxis)
Companion planting is partly traditional gardening lore. Where the reason is known, it is given.
Some of these explanations were machine-translated.
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