Tropaeolum is a genus of South American plants in the Tropaeolaceae family, including the common nasturtium. Some of the species have tuberous or rhizomatous rootstocks. The bright flowers of quaint shapes are usually freely produced on long stalks and the rapid growth of many of the climbers renders the Tropaeolum a very useful and decorative plant for many purposes.
Advice on growing Tropaeolum azureum, T. brachyceras, and T. tricolor, all winter growers is to plant them in a warm sunny place with neutral to acidic not too rich well drained soils. While in growth they need support for the climbing stems such as a trellis or a fence. Water well during growth, but allow them to be dry during the summer dormancy. Much of this information furnished by Bill Dijk.
Tropaeolum azureum is a slender tender climbing species from Chile with lavender-violet blue flowers with white eyes up to 40 mm (1.5 inch). The last photo shows the container with wire netting attached at planting time for support, which will avoid damage to the delicate new shoots later on. Photos by Bill Dijk.
Tropaeolum brachyceras is another half hardy native of Chile, with yellow flowers with purplish markings up to 25 mm (1 inch). Photo by Bill Dijk.
Tropaeolum pentaphyllum Climbing species produces masses of pink flowers, tipped with green, followed by dark purple fruit. It is commonly called 'Ladies legs', the flowers resembling pink legs with green shoes. Photos by Bill Dijk.
Tropaeolum peregrinum is an annual vine from Peru that can grow to 10' (3m). It tends to like cooler temperatures and does very well in mild climate. In the San Francisco Bay Area with a Mediterranean climate, the plant can be grown in full sun (spring to autumn), although with caution! I grow mine against a wall that gets half-day of sun and it does very well until heat-waves of above 95°F (35°C) for a few days nearly killed the poor thing. Before the heat-waves, it blooms prolifically and had a very nice and dramatic yellow. After the heat-waves, it doesn't look so good, but continue to bloom here and there once the temperature cooled down again. Away from the coast in warmer climate, it should be grown only in part-sun, although I have my doubts as to how warm the temperature can get before the plant croaks. Give the plant a good and rich soil and keep the roots moist and cool, no matter where you live. It can be grown in containers and does quite well. Supposedly, the plant sets seeds by itself, but despite my pollination efforts, the seed capsules abort. The first photo below shows a plant blooming in late autumn after summer sowing, grown and photographed by Rob Hamilton. The second and third photo is by Nhu Nguyen showing the side and frontal views of the flower.
Tropaeolum polyphyllum is one of the "standard" tuberous Tropaeolum species, if such a category is a tenable concept. The plant depicted originally came from Gossler's Nursery in Springfield, Oregon ca. 1990. Planted about 3' from a raised concrete patio, it methodically moved year by year until it now emerges from crevices around the margin of the patio. The tubers are probably under the patio at this point. With its gray-blue foliage and clear yellow flowers of some size, this is a very good garden plant. Plant it where the foliage can sprawl and spread; it doesn't seem to be a climber. The plant is self-fertile and sets viable seed once in a long while. Since this plant puts its tubers a long way below the soil surface, seed may be an easier method of propagation than bringing in a backhoe to lift tubers. The photo by Rodger Whitlock does not clearly depict the sprawling character of this tuberous nasturtium.
Tropaeolum tricolor from Chile and Bolivia is a half hardy plant with red, violet, blue or yellow flowers with greenish margins. This plant is sometimes referred to as Tropaeolum tricolorum. This one is long blooming and a favorite winter blooming plant in Mary Sue Ittner's Northern California garden. I grow it in a deep container that I plant in the ground nested in another pot and provide it with a trellis or fence to grow on. The first two photos by Bob Rutemoeller show the first blooms and then later when there were many more. The third taken by Kristina Van Wert is a close up of a flower from the Mendocino Coast Botanical Gardens bulb collection. The last two were taken by Bill Dijk.
