Corn salad

Light and exposure

In the cold season, give corn salad the brightest spot in the garden. At that time of year the sun sits low and daylight is scarce, and every hour of light counts toward forming nice tight rosettes. An open bed, with no shade cast by a wall or a hedge, suits it perfectly.

The earliest late-summer sowings are the exception. Under a still warm sun, an overly scorching position dries out the soil and stops the seeds from germinating. For these first sowings, a corner that gets a little early-afternoon shade, or a bed shaded by a neighbouring crop still in place, clearly improves emergence.

Watering

The key moment is at emergence. Corn salad seed germinates poorly if the soil dries out, which happens quickly with late-summer sowings. After sowing, keep the surface moist with fine, regular watering, in a soft rain, until the young plants are well up. A cloth or a light mulch helps hold that moisture.

Once established and once autumn arrives, corn salad asks for almost nothing. In a temperate climate the rains of the cold season are more than enough, and too much water on cold soil would even be counterproductive. In winter you stop watering and let the sky do the work.

Soil and repotting

Corn salad likes firm soil, rather compact, cool and clean. Unlike many vegetables, it does not need freshly dug and fluffed earth: sow it preferably after an already harvested crop, on soil simply scratched at the surface, then firmed down well after sowing. This close contact between seed and soil encourages germination.

There is no need to manure the bed for it. Soil too rich in nitrogen gives soft leaves that rot more easily in winter. Ordinary earth, neither too acidic nor waterlogged, suits it fine. A former spot for beans or potatoes, cleared of its residue, makes an ideal bed.

Temperature and humidity

This is corn salad’s great strength: cold does not scare it. It grows slowly but surely between 5 and 15 degrees, keeps going under grey weather and withstands sharp frosts, down to -10 or even -15 degrees for the hardy varieties. A touch of frost even firms up its flavour.

Heat, on the other hand, is what bothers it. Above 20 degrees germination becomes unreliable and the plants quickly bolt to flower once the days lengthen again. In a cool, damp temperate climate it is therefore perfectly at home, and it really is summer, not winter, that remains its impossible season.

Pruning and upkeep

Corn salad is not pruned in the classic sense, but its upkeep comes down to weeding. Its rosettes are small and low, quickly smothered by weeds. Hoe gently between the rows while the plants are young, without loosening the rosettes, which hold weakly to the soil.

Thin out if the sowing is too dense. Plants that are too crowded lack air, grow leggy and rot faster in damp weather. Leave a few centimetres between each rosette so they form nice round heads and stay healthy all winter.

Pests and diseases

Corn salad has few enemies, which is part of its charm. The main concern is powdery mildew, a white felting that appears when plants are too crowded and poorly aired, especially in a mild, damp late season. Prevention comes down to one thing: sow thinly, or thin out, to let air circulate between the rosettes.

Slugs are the other threat, particularly on the young tender plants in autumn. They can level a sowing in a single night. Collecting them in the evening, dry ash or mulch around the beds, and keeping watch after each gentle rain limit the damage. Rot can also affect rosettes in contact with waterlogged soil: well-drained earth and a not too dense sowing prevent it.

Propagation

Corn salad is grown solely from direct sowing in place, shallow. Sow on the surface or barely covered, under just a few millimetres of fine soil, then firm down hard with the back of a rake or a small board. This firming is essential: it ensures the seed-to-soil contact that triggers germination. Then keep moist until emergence, which takes one to three weeks depending on the warmth.

To save your own seed, let a few plants bolt to flower in spring. Corn salad flowers in small bluish clusters and readily self-seeds around the garden on its own. Harvest the seeds when they turn brown, dry them and keep them dry: they hold their germinating power for several years.

Month-by-month care calendar

Green Hub tips

• The secret of the first late-summer sowing is moisture: water fine and often, sow in partial shade and firm down hard, otherwise the seed will not come up.
• Sow thinly or thin out. Rosettes that are too crowded smother themselves, catch powdery mildew and rot as soon as the weather turns mild and damp.
• A touch of frost firms up the flavour of corn salad: no need to protect it, it is a genuine fresh vegetable of deep winter.
• Harvest by cutting the whole rosette level with the collar, and rinse carefully: the low leaves easily hold on to soil.