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.
Spinach (Spinacia oleracea) is divided into winter and spring varieties. There is also a kind called New Zealand, which is grown for midsummer. It belongs to a different genus (see below). To take the winter variety first. This has prickly seed. Sowings are made in late August and during September, in drills 9 in. apart, with the seed buried to the depth of 1 1/2 in. It is a good plan to have the land on which the Spinach is to be sown ploughed a week or two before it is wanted, and left to settle, as it prefers firm ground. Pickings begin as soon as the leaf is big enough, and in mild seasons continue all the winter. Winter Spinach is liable to a fungoid disease the nature of which is hardly yet understood, and no remedy known for it, except perhaps sulphuring the ground. When attacked, the plants go yellow at the leaves and gradually melt away. The earliest sowings are most frequently attacked, and it is a good precaution to put off one sowing to near the end of September. It is when spring growth commences that the winter Spinach produces its principal pickings, which continue until it runs to seed in June.
Spring Spinach consists of the round-seeded varieties, of which the Victoria is perhaps the most grown. Sowings commence early in the spring, and continue till June, after which it is no use sowing, because Spinach will not thrive during the hottest days of summer. [w. g. l].
Spinach is grown in cold greenhouses during the winter and spring months when a large space is available. The seed is sown in October in drills about 1 ft. apart in the ordinary way. Growth is slow at first, owing to the low temperature, but picking commences about the middle of March and continues till May, when the ground is cleared for Tomatoes. On warm, genial days the plants receive a good watering, and the ventilation is regulated according to the state of the outside weather. Women are chiefly engaged in picking the leaves, the cost being about 2 1/2d. per bushel, and 10 bus., each holding 18 lb. of Spinach, are picked in a day. Prices for early Spinach rule high, being often as much as 6s. to 9s. per bushel. [J. W].
Fig. 493. - New Zealand Spinach (Tetragona expansa).
This is a succulent trailing plant, with thick ivy-like leaves. It is raised under glass from sowings made in March. It is potted into thumb pots, or pricked into trays and planted out in late May or early June in rows 3 ft. apart, with 2-ft. spaces in the rows. When once established it grows quickly and covers all the ground. The leaves are gathered for market. It revels in the hot weather, wants frequent waterings, and succumbs to the first frost.
[W. G. L].