This section is from the book "A Dictionary Of Modern Gardening", by George William Johnson, David Landreth. Also available from Amazon: The Winter Harvest Handbook: Year Round Vegetable Production Using Deep Organic Techniques and Unheated Greenhouses.
By this name are commonly known two species of Tro-paeolum. T. mnjus is a hardy annual twiner, and there are several varieties, distinguished by their double or crimson flowers. T. minus is a hardy annual trailer, and a variety with double flowers, is a green-house evergreen.
Although strictly annual when grown in the open ground in this country, yet they are naturally perennial, as may be proved if they are grown in a greenhouse. The Major Nasturtium being the most productive, as well of flowers and leaves as of berries, is the one that is usually cultivated in the kitchen garden; the first two being employed in salads and for garnishing, and the last in pickling.
They flourish in almost any soil, but are most productive in a light fresh loam. In a strong rich soil, the plants are luxuriant, but afford fewer berries, and those of inferior flavour. They like an open situation.
They may be sown from the beginning of March to the middle of May; the earlier, however, the better: one sowing in the kitchen garden, and that a small one, is quite sufficient for a moderate sized family. The seed may be inserted in a drill, two inches deep along its bottom, in a single row, with a space of two or three inches between every two, or they may be dibbled in at a similar distance and depth. The minor is likewise often sown in patches. The major should be inserted beneath a vacant paling, wall, or hedge, to which its stems may be trained, or in an open compartment, with sticks inserted on each side. The runners at first require a little attention to enable them to climb, but they soon are capable of doing so unassisted. The minor may either trail along the ground, or be supported with short sticks. If water is not afforded during dry weather, they will not shoot so vigorously, or be so productive. They flower from June until the close of October. The berries for pickling must be gathered when of full size, and whilst green and fleshy, during August.
For the production of seed, some plants should be left ungathered from, as the first produced [are not only the finest in general, but are often the only ones that ripen. They should be gathered as they ripen, which they do from the close of August even to the beginning of October. They must on no account be stored until perfectly dry and hard. The finest and soundest seed of the previous year's production should alone be sown; if it is older the plants are seldom vigorous.
 
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