The Field Guideby Moss & MarrowThe Field Guideby Moss & Marrow
Also called kropsla, ijsbergsla, eikenbladsla, romeinse sla, little gem.
In the Netherlands, lettuce is in season May to October, at its best in June and July. After the harvest, Dutch stores carry it until November. In November, Dutch lettuce comes from store or from under glass, not from the field.
Field lettuce runs from May to October. In the shoulder months Dutch lettuce comes from unheated glass, and in winter from heated glass or Spain.
Field lettuce has a looser head, thicker outer leaves and more flavour than the pale glasshouse heads.
Vitamin K, folate and water. The darker and redder the leaf, the more beta-carotene and polyphenols. Around 95 percent water with potassium, so it hydrates as much as it feeds.
To get the most: Choose the dark outer leaves over the pale heart, and dress with oil: the fat helps the carotenoids across.
On our nutrient density chart, a normal serving of romaine lettuce (60 g) gives about half a day's vitamin K and about a third of a day's vitamin A, counting what your body absorbs. That puts it in the top 25% of the 244 foods we scored.
Content per NEVO, the Dutch food composition database. This describes what the food contains, not what it does for you.
Wash and spin dry just before serving. Braise the outer leaves of a butterhead with peas and spring onions instead of throwing them away.
11 producers in The Field Guide sell lettuce, according to their own website or shop list, each checked against our inclusion criteria and listed by province. Another 168 growers passed our bar for this food group; we have not yet recorded what each of them grows, so ask them or search the map.
Open on the map →Dates read on 2026-10-11. If a window on this page is wrong, tell us with a source.
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