RadishRaphanus sativus

The radish settles in wherever there are thirty centimetres free: at the edge of a bed, between two rows of carrots or leeks, at the foot of the tomatoes in May, in a window box. In spring and autumn, give it full sun; in July and August, prefer the partial shade of a row of beans or a wall, where it stays tender. It dislikes soils that dry out quickly or form a crust. Avoid sowing it where cabbages or turnips have just grown, as it shares their pests, and make the most of its speed to slot it in ahead of slow crops.

The radish is content with ordinary soil provided it is loose to ten or fifteen centimetres and fine on the surface. Scratch over the bed, remove stones and break the clods until the surface is fine, with no manure or young compost, which make the roots hollow and attract maggots. Soil manured for the previous crop is more than enough. In clay soil, mix a little sand or potting compost into the surface so the young roots do not hit a barrier. Rake just before sowing so the soil is fresh and crust-free, as the small seeds cannot push through a crust.

Spring radishes are sown from March under fleece, then in the open from April to mid-June and again from mid-August to the end of September: in July, they turn hot and hollow. Winter radishes, black or pink, are sown just once between 15 July and 15 August. Sow little and often, a metre of row every ten to fifteen days, in a one-centimetre drill, one seed every three centimetres, or broadcast very thinly over a small bed. Cover with half a centimetre of fine soil and firm. Germination takes three to six days depending on the temperature. Note the date so you do not forget the next row.

The radish is never transplanted, but it is happy to be hurried along. From late February, sow in a cold frame, under a low tunnel or under a cloche, in soil warmed by fleece laid a week beforehand, with a short, fast variety such as 18 jours or Cherry Belle. Ventilate as soon as the sun warms up, otherwise the seedlings become leggy. A sowing behind a window in a fifteen-centimetre-deep window box works too. Then choose varieties according to the season: round red ones in spring, half-long white-tipped ones in summer, the large round black ones for winter.

The radish is the king of balcony crops, ready in a month. A window box fifteen centimetres deep is enough for round varieties, twenty for half-long ones and thirty for winter radishes. Fill with ordinary potting compost mixed with a third of soil or sand, without fertiliser, sow in rows ten centimetres apart and thin to three centimetres. Put the box in the sun in spring, in afternoon shade in summer, and water every day or every other day: that is the only condition for success. A sixty-centimetre box, sown in two halves a fortnight apart, gives two bunches.

Sowing the whole packet at once and harvesting fifty radishes in the same week. Sowing thickly and not thinning, with superb leaves and no roots to speak of. Forgetting to water for three days: the radish turns hot, hollow or bolts. Sowing in the middle of a heatwave in a scorching corner. Digging in fresh compost just beforehand. Letting flea beetles riddle the leaves without watering or covering. Waiting until the radishes are as big as walnuts: by then they are already hollow. Harvesting a whole row instead of picking the largest as you go, leaving room for the others.

A successful radish has grown fast without a single day of thirst. Water with a fine spray from sowing, then every two days in spring and every day in summer, morning or evening, aiming for soil that is always moist in the top ten centimetres. Three litres per metre of row is enough if it is regular. A radish short of water hardens, goes hollow, turns hot and flowers; a sudden excess after drought splits it. Water the foliage too at the end of the day in hot, dry weather, as this discourages flea beetles. In containers, check every day with a finger pushed into the compost.

The radish needs no fertiliser: it lives on the soil's reserves for its four weeks, and excess nitrogen gives leaves at the expense of roots. A very fine mulch, dried grass clippings or hemp mulch one or two centimetres deep, spread as soon as the seedlings have two leaves, keeps the surface moist, prevents capping and spaces out watering. Do not lay a thick mulch; slugs hide in it and the seedlings lack light. For winter radishes, which take longer to come, a five-centimetre mulch in September keeps the coolness needed for tender roots.

Thin as soon as the seedlings are up, at the two-small-leaf stage, leaving one plant every three centimetres for round varieties, five for half-long ones and ten for winter radishes. It is a two-minute job that decides everything: too crowded, the radishes form no root. Pinch out the surplus seedlings between two fingers rather than pulling them, so as not to disturb the neighbours, then water. Hoe lightly once if a crust forms, but do not earth up or work the soil deeply. Remove plants that bolt; they will give nothing.

Flea beetles, small black jumping beetles, riddle the leaves with holes in hot, dry weather, especially in May and June. They hate damp: water with a spray in the evening and put fine insect-proof mesh over the sowing, edges well buried, which also blocks the cabbage root fly whose larvae bore into the root. Slugs attack the seedlings: collect in the evening, ring with ash, no thick mulch. Winter radishes, longer in the ground, are protected from the fly by the mesh and by rotation with the other brassicas, cabbages and turnips included.

Late February: first sowing under a cold frame or tunnel. March: sowing under fleece outdoors. April to mid-June: a small sowing every ten to fifteen days, thinning at emergence, mesh against flea beetles, watering every two days. Late June: last spring sowing, in partial shade. July: a break for pink radishes, sowing of winter radishes around the 20th, daily watering. Mid-August to late September: sowings of all-season radishes resume, milder than in spring. October: last harvests under fleece, mulching of winter radishes. November: lifting winter radishes before the hard frosts and storing in sand.

Pick as you go, as soon as the root is the size of a marble or a small walnut, pulling on the leaves while holding the soil down; the largest first, which gives the others room. A row is harvested over ten days, no more: beyond that, the radishes go hollow. The best way to extend the season is to sow little and often, from March to September, with a break in July for the pink ones. In October, fleece over the last sowings keeps the harvest going until All Saints' Day. Winter radishes, lifted in November, keep for three months in sand in the cellar.