Many tropical plant genera and species have been commercially available for years, but new uses, species and hybrids have pumped more life into them. Hippeastrum and banana plants (Musa and Ensete species) can bring a warm, exotic look to a grower’s product mix. These two tropicals add diversity whether they are used as specimen pot plants, patio plants or as part of landscape plantings.

Hippeastrum (Amaryllis)

Background

Amaryllis species and hybrids (Amaryllidaceae family, genus Hippeastrum) grown from bulbs have long been favorite flowering plants. What Americans call an amaryllis is actually a Hippeastrum. These plants are native to the tropical areas of Brazil where they are considered more of an evergreen perennial.

The flowering bulbs in the genus Amaryllis are native to South Africa and vary from Hippeastrum by differences in their inflorescence. These are not used commercially as Hippeastrum.

In subtropical climates (USDA Hardiness Zones 7b through 8) Hippeastrum bulbs flower naturally in April and May. Foliage matures and slowly fades during summer. In fall, bulbs go dormant (whether this is true dormancy is up to debate) until emergence of leaves and usually two buds per bulb each spring. Dormancy can be imposed by harvesting the bulbs, shipping temperatures, storage temperatures or drought.

Most Hippeastrum grown commercially for forcing are hybrids, but there are many species and hybrids that should be reconsidered as flowering pot plants and landscape plants. Some of these bulbs have been grown in Southern landscapes for years and are often referred to as the “lily of the South.”

Varieties

Hippeastrum x johnsonii, often referred to as Saint Joseph’s lily in the South, has a bright-red flower with a thin, white stripe down the center of each petal. A close relative is ‘Voodoo’ (Naughty Lady), which has a broader white stripe and recurved petals.

Many popular hybrids used as flowering potted plants will also do well in the landscape. These plants require well-drained soil and full sun for best growth.

If Hippeastrum won’t work for your customers as landscape plants, consider growing them as potted plants. Their popularity, especially as an alternative Christmas holiday pot plant, has steadily increased.

The sale of Hippeastrum bulbs for forcing occurs in late August and early September. The bulbs can be marketed as “dry bulbs” to be potted in soil or gravel by homeowners or sold in ready-to-plant kits with the bulb, pot and soil in a decorative box. The plants can also be sold as a finished flowering pot plant.

There are approximately 3 million Hippeastrum bulbs imported into the United States from the Netherlands. Several million are also imported from Israel, South Africa and Brazil.

Bulb forcing

Hippeastrum bulbs are planted in pots in October through January for production as potted plants. There is simultaneous emergence of four leaves and a 12-inch flowering stalk. The average forcing time to market stage is three to five weeks.

Bulb grades for commercial use are 20/22, 22/24, 26/28, 30/32 and 32/up centimeters in circumference. Flowering is regulated by bulb size (diameter or circumference and not by weight) with a minimum size of 20 centimeters (8 inches) in circumference.

The environments for bulb production and storage vary between growers and by the country in which they are produced. Bulbs produced in the Netherlands, Israel, South Africa and Brazil are harvested at different times of the year, resulting in storage times and temperatures that vary. These differences in harvesting have had a positive impact by providing a greater availability of bulbs at reduced prices. However, these differences have also increased the variability in growth and flowering during forcing. Because bulbs are brought out of storage for forcing or for sale as a dormant bulb, emergence and flowering may be highly variable.

Growers should pay careful attention to where the bulbs originated and the storage conditions they were exposed to before they were delivered. If bulbs are going to be stored before forcing, the storage temperature should not exceed 48°F and they should not be stored for more than 15 weeks. The minimum storage temperature is 41°F, which causes more rapid emergence and flowering. Varieties respond differently to storage times and temperatures.

High temperatures during forcing (77°F-86°F) hasten development and elongation of the leaves and increase growth of bulbs, but may prevent flowering. Low temperatures (54°F-63°F) cause the leaves to unfold and elongate slowly and bulbs are slow to enlarge with little floral development. Temperatures of 63°F-75°F induce intermediate vegetative growth and bulb enlargement and optimum flower emergence. Research has found that there is no effect of daylength on growth and flowering.

Bananas

Background

Ornamental bananas, both Musa and Ensete, have become important tropical landscape plants.

There are some taxonomic differences between the genera Musa and Ensete. Musa species tend to have more adventitious roots or sucker more readily than Ensete species.

There are hundreds of varieties of Musa with various forms, leaf sizes, shapes and variegation, heights and inflorescences. Some produce edible fruit. All grow best in full sun with ample water. Hardiness varies.

Bananas are relatively easy to grow from tissue culture. Most liners can be purchased in 72-cell trays. Depending on the variety and how the plants are to be used, the liners can be grown in 4-inch to 3-gallon or larger containers. Plants should be produced under 30 percent shade to full sun.

Musa ‘Little Prince,’ offered by Ball Horticultural Co., can be grown as a potted plant in a 4-inch pot. In the landscape it reaches a maximum height of 2 feet.

Other bananas can also be produced in large containers and used either directly in the landscape or remain in containers as specimen plants.

Bananas are pseudostems with flowering and fruiting stalks growing from underground rhizomes. The inflorescence arises from the pseudostem approximately 10 to 15 months after planting.

If flowering or fruiting is desired, pseudostems cannot be removed before development. If cold damage occurs but the pseudostems have not been completely frozen, they can be trimmed back and the foliage will emerge from the top of the cut pseudostems.

Bananas require large quantities of water and fertilizer for quality growth. A fertilizer high in potassium (i.e., 3-1-6) is recommended for best growth.

Top performers

Louisiana State University, University of Florida and Texas A&M University planted a banana variety trial four years ago consisting of six banana varieties (two of each dwarf, medium and tall varieties) from AgriStarts.

There are many varieties to choose from depending on their use. Three varieties that have performed well at Louisiana State University AgCenter, Burden Center research station (Zone 8b) were selected.

Musa ‘Ice Cream’ (Blue Java) is hardy to Zone 8 and can grow 15 feet tall. In spite of its height, its sturdy stem and root system stand up to strong winds. Leaves are silver-green and measure 4 feet long. Its blue-green fruit is medium sized with white flesh. The fruit, which doesn’t have the typical ‘Cavendish’ banana taste and texture, tastes as good as the name implies.

‘Dwarf Orinoco’ is a small, vigorous plant that is solid green and has a thick stem. It is hardy to Zone 7b. The leaves are 1 1/2 feet wide and 3 feet long. It produces thick skinned, short, round edible fruit. ‘Dwarf Orinoco’ withstands wind and is a plant that doesn’t overwhelm the landscape. It reaches 5-6 feet tall. Its edible fruit is thick skinned, short and round.

 

‘Basjoo’ is supposed to be the hardiest banana, to Zone 4. It has long, slender, bright-green leaves that measure 4 feet long and 1 1/2 feet wide. Its inflorescence is supposed to be one of the most beautiful of all bananas, but I would beg to differ. Plants reach 12-18 feet tall. It’s a nice landscape plant for temperate climates. ‘Basjoo’ has been advertised as one that can be grown in all 50 states. If anyone in colder Northern climates has successfully grown this variety in their landscape for more than two years, I would appreciate hearing from you.

- Jeff S. Kuehny

Jeff S. Kuehny is professor of horticulture, Louisiana State University, School of Plant, Environment and Soil Sciences, (225) 578-1043; This e-mail address is being protected from spam bots, you need JavaScript enabled to view it . The author acknowledges the support of Fred C. Gloeckner Foundation, Nurserymen’s Exchange and AgriStarts and the assistance of Allen Broyles and Sergio Sosa with the banana trials.

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