Grote Noordhollandse Corn Salad
Robust lamb's lettuce for autumn and winter harvests, even in the most challenging conditions.
About the variety. The Grote Noordhollandse variety forms large rosettes of narrow spatulate leaves, light green in colour and medium thickness. Cold- and weather-resistant, it tolerates mild frosts and stays productive when other crops stop growing.
Itinerário técnico
Um guia de cultivo passo a passo, da sementeira à colheita.
Sow direct half a centimetre to one centimetre deep, broadcast or in close rows, and firm the soil lightly on top. Germination takes ten to fourteen days in cool soil: above 20 °C it is poor and uneven, so the right window is late summer into autumn. It needs no fine thinning, because it grows well as a dense carpet. It forms a low rosette and grows well in a shallow pot or window box, outdoors through the whole winter.
It is undemanding and grows in poor soil as long as it is free draining and settled, at a pH between 6.5 and 7.5. Soil that is too fluffy hurts germination: firm the surface after sowing. Sown after a summer crop, it uses the bed without fresh preparation: just clear, level and firm it.
It is one of the hardiest crops in the garden and takes several degrees of frost without protection, tasting better after it. Heat, by contrast, makes it bolt straight away. It is the winter salad leaf par excellence. On the Portuguese coast it grows through the whole winter without trouble. Inland in Portugal and Spain night frosts do it no harm, but the summer there is too hot and dry for it. In France and Germany it is the classic autumn and winter salad: sow in August and September, and in a hard winter a fleece or a low tunnel keeps the leaf in good condition until spring. In Italy it is an autumn and winter crop in the centre and south, as in Portugal, and a spring and autumn crop in the north, where the Po valley winter is too hard to leave it outside unprotected.
It asks for little and an over rich soil works against it. Soil that was composted for the previous crop is enough, with no extra feeding. Excess nitrogen gives soft, watery growth with little flavour and much greater sensitivity to pests and cold.
Water lightly to keep the surface moist until germination, which is slow. Once established it needs very little water, and in winter rainfall usually suffices. Standing moisture rots the rosettes.
Sown densely, the crop covers the soil itself and keeps weeds well in check. The work is concentrated in the first two or three weeks: hand weed or run a hoe very shallowly between the plants. Avoid disturbing the soil once the canopy closes, so you do not damage roots or bring fresh weed seed to the surface.
Few pests trouble it in winter. Slugs and snails are the only serious problem and hide among the rosettes: collect them at night and use an ash barrier. Birds pull up the seedlings in the cold weeks: a light net over the sowing until the rosettes close up solves it. Also watch for aphids in a mild winter. Leaf miner can draw tunnels in the leaf in a mild autumn: remove the marked leaves and the plant carries on without treatment.
Downy mildew and botrytis can appear if the sowing is too dense and the winter very wet. Sow thinner than instinct suggests, ensure drainage and avoid watering over the leaves. In a very wet winter, a low tunnel open at both ends keeps the leaf dry without overheating it, which is what makes it bolt. Dark spots on the leaf edge in sowings repeated on the same spot are leaf spot: change beds every year.
Cut the whole rosette off at ground level with a knife once it has six to eight leaves. You can also pick individual leaves, but the whole rosette is the traditional and most practical form. Wash well, because the leaves sit on the soil and hold grit. Allow about 30 to 40 days from sowing to the first harvest of this variety. The reference colour is light green, and that is what tells you it is ready.
