
Leek, Allium ampeloprasum, is an old fashioned but traditional cool season vegetable. It is rare among home gardens, but has been in cultivation for thousands of years. It is one of the floral emblems of Wales, in conjunction with daffodil. In cooler climates, leeks may grow through summer for autumn harvest. They are only a cool season vegetable locally.
Leeks grow easily from directly sown seed, but are alternatively conducive to transplant. Therefore, they can start in flats while warm season vegetables are still producing. Then, they can transition to the garden early enough to mature before frost. Later phases which grow through winter are quite tolerant of mild frost. They might even be bigger and better.
Like several cool season vegetables, leeks are in no rush for harvest. Once mature, they can linger in their gardens for weeks without deteriorating or bolting. Like related onions, they prefer somewhat rich and loose soil. Until the winter rainy season begins, they need regular watering. Thrips can be more of a problem in other regions during warm weather.