Iochroma

( eye - oh - KROH - muh )

At-A-Glance Information

This genus is comprised of species of shrubs and small trees that produce tubular flowers in a variety of colors. Most species are native to Mexico and Brazil, and are cultivated in a variety of tropical and subtropical areas as landscape ornamentals. They are not particularly cold-hardy, but can be grown in sheltered areas of the garden or in greenhouses in areas with frost. Use these plants as specimens or accents in the ground or in containers, or use them in pollinator or hummingbird gardens to draw in wildlife. Take care when planting these tropical shrubs in the landscape, as all plant parts are poisonous to humans and pets if ingested.

Iochroma Species and Varietals

The genus Iochroma has about 34 species and is in the plant family Solanaceae, which means it is related to genera Solanum, Browalia, Cestrum, and Nicotiana. The best growing zones for these plants are USDA hardiness zones 8-11 or Sunset growing zones 6-26, H1 and H2. To find your zone, click here: Zone Map.

Iochroma arborescens (Gallinero, Mata-Gallina, Ruta-de-Sabia, Hollowheart, Wild Tobacco, Siyou, Bastard Sirio, Galan Arboreo, Tabak Djab, Tabaco de Monte)
These plants are native to Central America, South America, and the Caribbean and form large shrubs or small trees up to 33 feet tall. Foliage is green and fragrant flowers are white. This species is considered invasive in India's Western Ghats.

Iochroma calycinum (Violetbush, Teta de Vaca, Tubeflower, Mini Angel's Trumpet)
These shrubs grow primarily in the wet tropical biome in Ecuador. They produce green foliage and purple tubular flowers and grow to reach a height of 5-10 feet tall at maturigy. Cultivar 'Vlasta's Surprise' is a choice garden ornamental.

Iochroma cyaneum (Iochroma tubulosa, Iochroma tubulosum) (Blue Trumpet Flower, Mini Angels Trumpet, Purple Tube Flower)
This species forms a broadleaf deciduous or semi-evergreen perennial plant with green foliage. Purple flowers emerge during most seasons, attracting bees and hummingbirds to the garden. Needs dappled shade and even moisture to thrive. To 8 feet tall and wide. The straight species has dark purple blooms.

'Indigo'
With frilled dark reddish-purple flowers.

'John Miers'
With reddish-purple to maroon flowers.

'Royal Blue'
With blue-purple flower inflorescences.

'Royal Queen'
With reddish-purple flowers that bloom in packed inflorescences.

'Sky King'
Flowers are light purple to lavender in color.

'Trebah'
With pink-purple long, tubular flowers.

Iochroma spp. Hybrids (Hybrid Iochroma, Hybrid Mini Angel's Trumpet)
This group of Iochroma plants are the results of either intentional or naturally-occurring cross-pollination between Iochroma species.

'Ashcott Red'
To 3-5 feet tall and wide, with bright red, profuse flowers.

'Burgundy Bells'
Upright shrub with burgundy flowers. Tolerant of heat, can be grown indoors.

'Frosty Plum'
White-edged plum-colored flowers.

'Ruby Red'
With bright, cherry-red flowers.

'Sunset'
With peach to salmon-colored blooms.

'Wine Red'
This cultivar produces merlot-colored blooms.

Caring for Iochroma

Iochroma shrubs and trees should be planted in full sun to shade, depending on the climate. Along coastlines and in tropical regions, they can tolerate full sun, but in temperate zones, they will need to be protected from full sun, frost and reflected heat from walkways and buildings. Ensure that soil is both well-draining and moisture-retentive before planting; if local soils are overly clay, do not drain well, or are hydrophobic, these plants will not grow well. Make sure to amend the planting area with plenty of organic material and/or compost before installing. Iochroma plants do well in soils with a pH of around 5.5. After planting, apply a thick layer of mulch around the base of the plant (keeping it a few inches away from stems). This will help to suppress weed growth, retain soil moisture, and maintain constant soil temperatures. Water newly planted shrubs and trees regularly to help them establish a strong root system. At maturity, these plants will need regular waterings; soil should only be allowed to dry out completely very infrequently.

In areas that experience frost conditions, Iochroma plants will need to be brought indoors or placed in a greenhouse over the cooler months of the year. They are hardy to around 25 degrees Fahrenheit, when they will start losing leaves. Plants recover well from frost damage in spring, however. The best time to prune Iochroma trees and shrubs is in early spring, before new growth has pushed out for the year. During this season, regularly remove dead or crisscrossing branches and thin out the plant to increase air circulation throughout the canopy. Iochroma plants do not need to be fertilized; a simple application of organic compost in springtime is enough to provide nutrients for the growing season. These plants can survive in the landscape for a few decades before needing to be replaced.

Caring for Iochroma Indoors
Provide Iochroma plants with as much natural light as possible. Soil should be well-draining and moderately fertile. Ensure that there are adequate drainage holes in the bottom of the container before planting. Water plants regularly, lessening waterings in late fall and wintertime when the plant is in its dormant phase. Prune away any dead, damaged, diseased, or crossing branches and thin out the canopy as necessary to improve air circulation and light penetration. Fertilize yearly in springtime with a balanced, slow-release fertilizer.

Propagation

Iochroma can be propagated either by using cuttings or from 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, and will take a bit longer to reach an age when it will flower. To propagate your Iochroma tree or shrub, follow the instructions below:

Propagating Iochroma 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. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
In 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 3-6 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 shrub.

Propagating Iochroma 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. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. Iochroma seeds are located inside of the fruiting bodies produced by plants after flowers have faded; they are typically present in late fall, and seeds are ripe when berries begin to fall from the plant naturally. Collect as many berries as possible, and bring them indoors to work with them. Cut fruits open, and carefully remove seeds from the flesh. Rinse them under water to remove any remaining flesh.
When ready to sow, place seeds in a bowl filled with lukewarm water, and let soak for 24 hours.
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 15-30 days 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 70 and 80 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.

Iochroma seeds are contained inside of the bright orange to yellowish berries produced by plants after flowers fade.

Iochroma seeds. They are very tiny, and there are typically around 50 within each berry.

Problems and Pests

Certain species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Iochroma doesn't commonly suffer from any serious pest or diseases, but it can be susceptible to the following issues if the right growing conditions aren't met: