Tropaeolum

( trop - PEE - ol - um )

At-A-Glance Information

Tropaeolum, or Nasturtium, is a genus of flowering annuals and perennials that needs regular water. They are considered old-fashioned, and are favorites of gardeners in many regions. They are native to South America and grow rapidly. Flowers are typically brightly colored with rounded petals. Use Nasturtium to fill in areas of the yard that are bare, to clamber over fences, trellises or other structures, or alongside vegetable garden spaces. Nasturtium also does well in mixed beds and borders, in rock gardens, as edgings, or as a groundcover.

Tropaeolum Species and Varietals

The genus Tropaeolum is the type genus member of the plant family Tropaeolaceae and includes about 80 species. The best growing zones for Nasturtium vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Tropaeolum incisum
These plants produce flowers with flaring petals in shades of yellow and peach and creeping or climbing stems. Foliage is deeply divided and greyish green. Blooms appear on the plant between the months of September and February.

Tropaeolum minus (Dwarf Nasturtium)
Endemic to mountainous areas of Ecuador and Peru, and reaches about a foot tall and 30 inches wide at maturity. This species is the smallest in the genus. Varietal 'Baby Orange' is a choice garden cultivar.

Tropaeolum majus (Garden Nasturtium)
This annual grows in all zones and includes two main types: climbing types (that reach 6 feet via coiling leafstalk) and bushy types (which reach 1.5 feet tall and just as wide). Flowers are fragrant and come in maroon, red-brown, orange, yellow, red, and creamy white. There are single and double-flowered varieties available. Young leaves, flowers, and seedpods can all be used in salads to add a peppery flavor. They are easy to grow in most soils and bloom in early springtime. They are somewhat drought tolerant and need `full sun or light shade.

Tropaeolum peregrinum (Canary Bird Flower, Canary-Creeper, Canary Nasturtium)
This perennial species grows well in zones 15-24, H1 and H2. It climbs to 10-15 feet long and has frilled yellow flowers. Sow in spring for summertime bloom. Provide a support for its climbing nature. This species requires light shade and are frost-tender.

Tropaeolum polyphyllum (Soladito Grande de la Cordillera)
These plants are endemic to Chile and Argentina and have grey-green foliage that is deeply lobed. Flowers are borne on long, slender stalks and are golden yellow. Plants reach Hardy down to -4 degrees Fahrenheit. Most plants in this species are relatively decumbent, growing as a groundcover-type plant unless given a structure to climb.

Tropaeolum speciosum (Flame Flower, Flame Nasturtium, Coralito, Quintralito, Voqui)
Native to Chile, these plants are hardy perennials with wiry stems that reach up to 10 feet long. They will flower profusely in sunny areas, producing scarlet, funnel-shaped flowers that have spurs. Petals are clawed and widely separated. After flowers fade, red calyces remain, curling back to reveal three bluish berries.

Tropaeolum tricolor (Three-Coloured Indian Cress, Chilean Nasturtium, Soldadito Rojo, Relicaro)
These plants undergo a summer dormancy each year in their native range (Chile), and produce thin, straggly stems that can reach up to 10 feet long. Leaves are green and nearly circular with deeply cut lobes, and flowers are narrowly funnel-shaped. Blooms are red with yellow interiors, tipped with a dark band.

Tropaeolum tuberosum (Mashua, Mashwa, Anu, Cubio, Tuberous Nasturtium)
These plants are grown in the Andes (mainly in Peru and Bolivia), cultivated for their edible tuber roots. Roots are eaten cooked or roasted as a vegetable. These herbaceous perennial climbers reach between 7 and 13 feet tall, and has brightly colored tubular flowers and green foliage.

Caring for Tropaeolum

Grow Tropaeolum plants in a space in the garden that receives full sun. Ideally, these plants appreciate between 6 and 8 hours of sun each day. They can tolerate some shade (3-6 hours of sun), but will not bloom as profusely. In warmer climates, these herbaceous plants like to get some afternoon shade when temperatures are at their peak (typically between 2 and 3 PM). Ensure that soil is well-draining, lean (relatively infertile), and has a pH of between 6.0 and 8.0 (slightly acidic to slightly alkaline). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, Nasturtium plants appreciate consistent waterings, especially if they are grown in containers. They are somewhat drought-tolerant, but will begin to drop flowers and produce spindly foliage with prolonged dry soil.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flowers to neaten up the appearance of plants and encourage reblooms (unless you will be collecting seeds for propagation). For annual species or perennial species grown as annuals, plants are typically pulled and composted at the end of the growing season. In spring, perennial species can be cut back to trigger vigorous new growth.

Propagation

Tropaeolum, or Nasturtium, can be propagated by cutting or seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant, especially if you are propagating a hybrid cultivar. To propagate your Nasturtium, follow the instructions below:

Propagating Tropaeolum by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
Harvest your seeds. The seed heads on plants are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 2-6 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Tropaeolum by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand.
In early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 3-4 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new plant.