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.
The Broccoli (Brassica oleracea botrytis asparagoides) is closely related to the Cauliflower, but is hardier. The white or creamy-headed varieties are frequently mistaken for Cauliflowers, but they appear at a season of the year when the Cauliflower proper is under protection.
On well-worked grounds from 10 to 16 tons of heads of Broccoli may be secured from an acre of ground. The individual heads will weigh from 2 1/2 to 3 lb. each, and as many as 10,000 heads can be obtained from a similar area. To secure the best results the soil must be deeply cultivated and heavily manured. Broccoli, being gross feeders upon the potash, lime, and phosphoric foods in the soil, tend to impoverish the land. These foods should therefore be supplied by well-rotted stable manure and dressings of 4 cwt. of kainit, or 1 cwt of sulphate of potash to the acre, especially if the land is naturally light. In heavy soils, well and deeply worked, there are inexhaustible natural supplies of potash, and in such cases a dressing of superphosphate - 4 to 6 cwt. to the acre - would be better. A dressing of lime on land that has been previously heavily manured is highly beneficial.
Broccoli must be considered under the heads of White and Sulphur-tinted Section, Purple Section, and Sprouting Section.
Veitch's Self-jwotecting is a good white Broccoli which comes in after Autumn Giant Cauliflower. The leaves fold over the head, protecting it against the effects of frost if it does not come too severe. In fairly mild weather it will last till Christmas. In the White and Sulphur section come the spring varieties, seed beds for which are made in May and plantings in July and August. These heart in during May. They will weather any but abnormally hard winters. Sometimes additional protection is given to the heart by turning the rows towards the north, either with a plough or by digging soil away from the north side. This serves to protect them from the early sun after a frost, and the leaves lie over the heart. The process always has the effect of somewhat checking the growth. The chief place in England for this class of Broccoli is Penzance, where the plants come in earlier than anywhere else, Cornish heads having made quite a name for themselves. This class of Broccoli is cultivated with success, however, in other parts of England and in Scotland.
In the Purple Section the chief is the Purple Cape (fig. 464). There are two varieties, the Early and the Late. These are very old varieties of Broccoli, formerly much more cultivated than now, the Autumn Giant varieties having introduced too strong a competition with them, especially as regards the Early Cape variety, which comes in during September and October, and may be said now to be out of cultivation. The late Purple Cape variety, which begins to turn in about Christmas time, and continues, according to the clemency of the season, to come on till April, has many among the public who are fond of it. Seed beds should be made in May, and plantings up to middle August at a distance of 2 ft. 6 in. by 21 in. Cape Broccoli is sometimes sent to market docked in the same manner as Cauliflowers. It looks very pretty tied in bunches. For this purpose the outside leaves are bent back to form a handle, while the inside leaves are clipped close to the flower.
Bunches are made consisting of six, eight, or twelve heads, according to size, by laying them over a stiff rod, with the heads level at the face. If the different tints in which the flowers come are well mixed the effect is attractive.
Heads make 1s. 6d. to 2.s. per dozen. Bunches, 9d. to 1s. [W. G. L].
The "Cabbage Broccoli", or "Chou de Burghley ", is said to be a cross between a Cabbage and a Broccoli. It can be used as a Cabbage in winter and as a Broccoli in Spring, if allowed to mature the heads. Seeds are sown in April and May. It is not a market crop.
Fig. 464. -Broccoli - Purple Cape.