It is sometimes raised and blanched as follows: Sow the seed at the bottom of trenches made about six inches deep, twelve inches wide, three feet apart, and of a length according to the supply required. At the bottom of the trench, thoroughly mix a small quantity of well-digested compost, and sow the seeds in small groups, or collections (three or four seeds together), at about twelve or fifteen inches apart, and cover them an inch or an inch and a half deep. When the young plants have acquired three or four leaves, they should be thinned out to single plants. During the summer, keep them free from weeds; and, as they require much moisture, it is well to water frequently, if the weather is very dry. In September, the plants will have attained their growth for the season, and be ready for blanching; which should be done in a dry day, and when the plants are entirely free from dampness. It is thus performed: The leaves of each plant are carefully and lightly tied together with strong matting; keeping the whole upright, and the ribs of the leaves closely together. The plant is then bound with twisted hay-bands, or bands of straw, about an inch and a half in diameter; beginning at the root, and continuing the winding until two-thirds or three-fourths of the height is covered. If there is no heavy frost, the leaves will blanch quickly and finely without further pains: but, if frosty weather occurs, it will be necessary to earth up about the plants, as is practised with celery; but care should be taken not to raise the earth higher than the hay-bands.
One method of blanching is simply to tie the leaves together with matting, and then to earth up the plants from time to time like celery; beginning early in September, and adding gradually every week until they are sufficiently covered. Those, however, blanched by the banding process, are superior, both in respect to color and in the greater length of the parts blanched.
Another practice is to earth up a little about the base of the plant, tie the leaves together with thread or matting, and then envelop the whole quite to the top with a quantity of long, clean wheat or rye straw, placed up and down the plant, and tied together with small cord or strong matting. The leaves will thus blanch without being earthed up, and speedily become white. This process is a good one, is economical, and presents a neat appearance.
"In either of the methods, it is very necessary to be careful that the plants are perfectly dry before they are enveloped in their covering: they will otherwise rot." In about three weeks after being tied up, the cardoons will be fit for use.
Harvesting.—When the stems and midribs of the leaves are thoroughly blanched, they are ready for use. Until the occurrence of severe weather, the table may be supplied directly from the garden: but, before the closing-up of the ground, "the plants should be taken up, roots and leaves entire, and removed to the cellar; where they should be packed in sand, laying the plants down in rows, and packing the sand around them, one course over another, till finished. In this way, they not only keep well, but become more perfectly blanched."
To raise Seed.—Allow two or three plants to remain unblanched, and leave them in the ground during the winter, protected by straw or other convenient material. They will grow to the height, and flower and seed, as before described. One plant will afford sufficient seed for any common garden.
Use.—"The stems of the leaves, as well as the mid-ribs, when blanched, are used for soups, stews, and even for salads, in autumn and winter. The longer these parts of the plant are, and the more rapidly they are grown, the more they are esteemed, on account of their greater crispness, tenderness, and color." The "Gardener's Chronicle" gives the following directions for dressing them:—
"When a Cardoon is to be cooked, the solid stalks of the leaves are to be cut in pieces about six inches long, and boiled, like any other vegetable, in pure water (not salt and water), till they are tender. They are then to be carefully deprived of the slime and strings that will be found to cover them; and, having been thus thoroughly cleansed, are to be plunged in cold water, where they must remain until they are wanted for the table. They are then taken out, and heated with white sauce, or marrow. The process just described is for the purpose of rendering them white, and of depriving them of a bitterness which is peculiar to them. If this is neglected, the cardoons will be black, not white, as well as disagreeable." M'Intosh remarks, that, when skilfully prepared, they form an excellent and wholesome dish, deserving far more general notice.
In France, the flowers are gathered, and dried in the shade; and, when so preserved, are used as a substitute for rennet, to coagulate milk.
Varieties.—