People come to grief with Broccoli because they will treat it like Cauliflowers. Botanically the same, the two plants are, culturally, wide asunder. To grow a Cauliflower well you want a deep, rich, loose, moist soil; without it, the plants "button." Now let a man who wants Broccoli to stand the winter grow his plants through the summer in deep, rich, loose, moist, soil, and he will very likely be left lamenting.
It is because people insist on treating Broccoli like Cauliflowers that so few of these delicious vegetables are seen in gardens and allotments in spring. The order of use for Winter Greens should be: Autumn, Brussels Sprouts; early winter, the same, with Savoys; late winter, Kales; spring, the same, with Broccoli. Generally it works out: Brussels Sprouts, Savoys, Kales, nothing.
There are plenty of varieties of Broccoli which have the elements of hardiness in them. What they want is bringing out. Now, the bringing-out process is not effected by growing the plants as large as possible; rather is it suppressed. To get Broccoli hardy the plants should be raised sturdily and then grown in firm, rather poor, soil.
There is no occasion to raise spring Broccoli in heat; on the contrary, it is a mistake. The very most that should be attempted in the way of nursing is a box and a cold frame, and this should only be tolerated on those dry soils in which, summer planting being out of the question, May or early June planting becomes advisable. Generally, an outdoor sowing in March and another in April settle the question.
Writing, as I do, after a cycle of dry seasons, I am fain to incline a sympathetic ear to those who speak of getting their Broccoli along fairly early. After a series of years, in which a sun-baked, iron-bound soil has rendered summer planting a very unsatisfactory business, it is natural that growers should want to have their plants ready for putting out in May. There is no harm in it, provided the soil is not so loose and rich as to encourage rapid, soft growth - then there is every harm in it.
If Broccoli plants are put between Potatoes, it should be between early, short-topped varieties; and when the Potatoes are removed the soil should be rammed firmly around the Broccoli.
There are now Broccolis to give a supply for eight months in the year, but many do not trouble about autumn sorts, preferring to rely upon Cauliflowers. It is from March to May that Broccolis are most useful. Leamington and Late Queen, with change dishes of Purple and White Sprouting, will cover the period. I may, however, mention a few other varieties which I have grown, principally connected with the names of prominent seedsmen. Cannells' Early Spring White and Cannells' Late Spring White have proved to be valuable stocks, giving, between them, a supply of delicious hearts for many weeks. Carters' Spring Mammoth is a large and good sort. Suttons' Eastertide is a splendid mid-spring Broccoli.