DESCRIPTION: This is a large group of tender annuals and perennials that are found wild from Mexico to Chile. Some are bushy, self-branching plants that grow 1 to 1½ feet high and some are climbing or trailing plants, growing 4 to 6 feet. The rounded, peltate leaves grow up to 2 inches across. They are waxy green and some varieties are splashed with white. The fragrant flowers are shaped irregularly and grow 2 to 3 inches across. They are colored rose, pink, red, orange, or yellow. Plucking off the dead flowers as well as cutting for bouquets or culinary purposes increase bloom. The seeds of the large flowered annual Nasturtiums make pleasant pickles if picked green and the leaves may be used in salads and sandwiches. T. majus, the common Nasturtium, is popular for planting in gardens, window and porch boxes and pots. There are single and double flowered varieties, climbing and dwarf forms and those with variegated foliage. Even though this plant is a perennial, it is easier to treat as an annual. The Nasturtium is also known as Indian Cress. The young leaves, buds and flowers have a appetizing nippy taste that comes from a mustard-oil component. T. peregrinum, the Canary-Bird Flower or Canary Creeper is an annual, climbing kind with yellow flowers. T. speciosum, the Flameflower, is a perennial climber. Its delicate shoots are covered with apple green foliage. It produces scarlet flowers, which are followed by dull red seedpods revealing turquoise-blue seeds as large as peas. T. tuberosum, Anyu, is a half-hardy perennial that is hardly seen in this country. It is grown in the mountains of South America for its edible tubers. This vine climbs high, anywhere from 6 to 8 feet on banks and trees. The flowers have long stems and are yellow with red spurs.
POTTING: The tender kinds may be grown outside in mild climates, though they won't thrive where summers are very hot. They may also be grown in pots filled with loam, leaf mold and sand. When they've finished flowering, water should gradually be withheld. They should be stored safely from frost until they start new growth the following spring. The annuals are grown in well drained, moist soil and they should have sun half the day or more. T. speciosum, the Flameflower, should be planted in peaty soil or leaf mold, mixed with broken sandstone. The bed should be on the north side of a hedge, the foot of a cool wall, or some low evergreen shrub. The roots should be laid horizontally on the bed and covered with 4 or 5 inches of the special soil. Anyu, T. tuberosum, grows best in sun or light shade in mountain highlands or cool gardens. The tubers may survive the winter under deep snow, but store a few in a cold root cellar just in case those in the garden don't make it. Throughout the growing season, the edible flowers may be picked. The tubers should be mulched and dug up as late in the fall as possible. T. majus, Nasturtium or Indian Cress, are perennials in mild climates; otherwise, they are frost-tender annuals. They need full sun and fairly cool weather, but they produce a lovely, short lived show of color in hot summer areas if grown in partial shade. To harvest, snip off leaves and flowering stems near ground level to maintain a neat appearance. New growth will quickly replace the removed foliage, flowers and buds.
PROPAGATION: Seeds may be started inside at a 65-degree temperature. They should be sown in individual pots, 6 to 8 weeks before it is safe to plant outside. Seeds may be sown outside where they are to grow when the soil is warm. Seeds of Anyu are hard to find, so ask your botanical garden to send for them for you. Start the seeds or tubers early indoors and transplant after danger of frost. Be careful when moving them, their roots are very delicate. Seeds of Indian Cress should be soaked for 12 hours, dried, and sown outdoors in warm, well-drained soil after danger from frost has passed.
VARIETIES: T. majus (Nasturtium or Indian cress - The old Gleam Hybrids have long, trailing runners that can be draped over a trellis. Modern dwarf bush Nasturtiums, such as Jewel, are classified as T. minus. They are prettier and better for flowers because the blossoms grow out beyond the leaves); T. peregrinum; T. azureum; T. brachyceras; T. Deckerianum; T. peltophorum (Lobbianum); T. pentaphyllum; T. polyphyllum; T. speciosum (Flameflower); T. tricolor; T. tuberosum (Anyu).