This section is from the book "Commercial Gardening Vol4", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Considerable breadths of Onions are annually sown in the Evesham district, making a total of 150 to 200 ac. Generally the crop is a paying one, but occasionally prices are so low after the early part of the season that many acres are never cleared, and the Onions are dug in. With February, the young Onion season commences, and their pungent odour may be detected all around Evesham. At the station they impregnate the air as they wait in trucks to be conveyed to the industrial centres northward. Lorries and spring carts laden with them hurry along the streets and roads; they are set down in heaps and hampers in the wholesale markets; down the side streets leading to the market gardens, which literally invest the town up to the walls of its houses, groups of women are discovered in sheds and outhouses, washing, bunching, and tying this medicinally valuable, if odoriferous, esculent; and their presence and occupation may be known long before there is ocular demonstration.
Seed is sown - usually the "White Tripoli" - in July in drills about 9 or 10 in. apart by means of the drill; and besides a little hoeing in late summer, they require and receive no further attention. Those Onions that have grown very freely from any cause are sometimes wholly destroyed by a severe frost - say 25 degrees of frost; so the object kept in view is to have them well grown before December, but not "rank" or overgrown. [J. U].
Perhaps the worst is the Onion Maggot (An-thomyia ceparum), which attacks the young bulbs, and causes the drooping and yellowing of the leaves. Wireworms and other grubs also interfere with the roots in poorly tilled soil. One of the best preventives, and at the same time an excellent cultural operation, is to use the hoe frequently between the rows. This detaches the eggs of the maggot from the young bulbs before mischief is done. The grubs of Wireworms, etc, are also brought up on the surface in view of the birds, which soon destroy them. Strewing soot along the rows, or spraying with paraffin or quassia emulsions, may also be tried, but they are inferior to hoeing, and are probably more costly on the whole. [J. W].