Broccoli, a well-known and much-esteemed garden vegetable, one of the many varieties which cultivation has produced of the Brassica oleracea, the common kale or cabbage. Broccoli is said to have been originally brought to Italy from Cyprus about the middle of the 16th century. Its name is Italian. It is merely a variety of the Cauliflower (q.v.), with the same general characteristics, but a harder constitution, which enables it to withstand all but our severest winters. Many improved sub-varieties have been introduced within the past fifteen or twenty years, with greater delicacy of flavour and purity of colour, while the original hardy constitution of the race has remained unimpaired. Some of the varieties are early in coming into use from the time of sowing, and others late, and by a judicious selection and a careful study of the times at which each should be sown, broccoli may be made to span the period when cauliflower ceases, in October or November, till it may again be had in June. The trade in broccoli during winter and spring is very great. All British markets are supplied chiefly from Penzance in the early months of the year, the winter climate there being particularly favourable to its early production. The market-gardeners around Edinburgh are noted for the high excellence of the broccoli they produce in the later spring months, and are able to keep up the supply after that of the southern growers fails, and till the first crops of cauliflower come in. See BRASSICA.
In the cultivation of broccoli the seeds are sown in the open ground in April and May, thinly, so that the plants may not become crowded while they remain in the seed-bed. Deep rich loam is requisite to produce the best quality. The plants are finally planted out in June and July, at distances of from two to three feet apart, according to the vigour and bulk eventually attained by the individual sorts. Frequent stirring with the hoe or the fork between the plants is conducive to vigorous growth. In severe winters it is necessary to protect the plants by some means from frost. The most usual means practised is that of digging the soil away from the northern side of each plant, and laying the latter with an angle towards the north. The overhanging leaves prevent the lodgment of rain and snow in the hearts, and offer some protection also against frost, but the size of the heads is usually somewhat diminished by the check administered to the growth. When only small quantities are grown, they may be effectually protected by spreading litter over them when frost is severe, but in the case of large quantities this would prove too laborious and costly.