This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
Under the heading of Nasturtium (see p. 73) some species of Tropaeolum (T. majus and T. minus) have already been described, because they are mostly known under that name. The "Canary Creeper" is another species of annual growth with climbing stems, divided leaves, and golden-yellow flowers. It is variously known as T. peregrinum, T. adun-cum, and T. canariense, and is easily raised from seeds sown in gentle heat in March. The young plants are largely sold in pots in April and May, the frail stems being held up with a twig or two.
T. Lobbianum, with roundish leaves and long-spurred yellow flowers spotted with scarlet, may also be raised from seeds. There are many garden forms, some having dazzling scarlet or crimson flowers and deep-green leaves, and they are particularly cheerful during the winter. The hederoefolium section, with ivy-like leaves and scarlet flowers, are easily propagated from cuttings of the side shoots inserted in sandy soil in a temperature of 60° to 70° F., and produce nice sturdy plants that may be sold in small pots early in the year. When the dwarf varieties are raised from seed they are sold in shallow boxes in market, the plants being afterwards retailed in patches or whole boxes according to the class of customer.
Fig. 250. - Tropaeolum speciosum.
Amongst the Tropaeolums stocked by nurserymen, one of the most popular is T. speciosum, the Flame Flower (fig. 250), having thong-like roots and tubercles, climbing stems with deeply cut leaves, and brilliant scarlet flowers. It must be grown in cool moist places as it hates hot sunny positions. Other perennial Tropaeolums are pentaphyllum, vermilion; poly-phyllum, bright yellow, with its variety Leichtlini, orange; and tuberosum, scarlet and yellow, with pear-shaped crimson speckled tubers.