The leek is a valuable vegetable for winter and spring use and is often grown to replace onions when the last of the stored crop has been eaten. Sow the seeds outdoors in late March or early April on a prepared bed. A seed bed prepared for cabbage and lettuce sowings is suitable. Prevent annual weeds from smothering the grass-like seedlings, and water, should May be a dry month. The seedlings are dug up and moved to their growing positions in June or July. June planting is preferable.
For leeks of good size, a well-manured or well-composted soil is necessary.
Mark the rows with the garden line at 45cm (18in) apart. The usual planting tool is a blunt-nosed dibber, such as may be made from an old spade handle. Make the planting holes 23cm (9in) apart in the rows and sufficiently deep so that only the tops of the plants show above the soil when one plant is dropped into each hole. After planting, simply fill the holes with water. This washes sufficient soil down on to the roots; more loose soil fills the holes when the rows are hoed a week or two later. Following planting, inspect the bed for a day or two and replant any plants which may have been pulled out of the holes by birds. Mulching with sedge peat or, on rich soils, with weathered sawdust, in late July, saves all further cultivation. Leeks are left in the soil throughout the winter in the same way as parsnips.
Should the ground be needed for another crop in February or March, any leeks still in the soil may be lifted and heeled into a trench. All leeks should be used 1 before May.
The leek is a favourite vegetable among exhibitors and for this purpose, seeds are sown in gentle heat in the greenhouse during January or February. The seedlings are pricked off into fairly deep trays and each seedling is allowed 9 sq cm (12 sq in) of space. The seedlings are hardened off gradually in the cold frame for planting out in early May. Some keen showmen prefer to prick the seedlings into small clay pots and to pot on into the 13 or 16cm (5 or 6in) sizes.
To obtain leeks blanched to a length of 60cm (2ft) or more, the plants are grown in trenches prepared similarly to those in which single rows of celery are grown (see Celery). The preparation of the trenches calls for deep digging and the addition of well-rotted manure or alternatives such as garden compost or spent mushroom compost. The trenches are spaced lm (3ft) apart with 30cm (12in) between the plants. Soil from between the rows is drawn up towards the plants as they grow to form a steep ridge. Liquid manure feeds are given as well as frequent top-dressings.
‘Musselburgh’ and ‘The Lion’ are good standard varieties. The pot leek is a northern speciality.