Costus spectabilis care infographicThe Costus Spectabilis are perennial plants with gorgeous yellow trumpet-like flowers. This African flower rises from the garden soil like a majestic burst of the glorious sun, encouraging many to keep this precious plant in cultivation.

As the national Nigerian flower, the Costus Spectabilis is even more beloved when masses of brilliant golden trumpets flood the grounds during its growing season.

What Is a Costus Spectabilis?

The Costus Spectabilis is a remarkable rhizome that produces intriguing foliage with a shimmering golden yellow flower at the center. The Yellow Trumpet is an excellent plant for cultivation, even for gardeners with cooler climates, as they can be easily stored indoors when the cold forces them to go dormant.

Costus Spectabilis Care

The Costus Spectabilis is easy to care for and requires little maintenance. Just like most tropical plants, the rhizomatous geophyte has certain requirements that, when met, make the plant thrive.

– Water

The Costus Spectabilis requires regular and moderate watering. The watering amount is preferably abundant for plants that receive more light exposure. The plant prefers to be hydrated well, so the soil should never be allowed to dry out.

The Yellow Trumpet may like moist soil conditions but will also acquire root rot if the rhizome constantly sits in waterlogged soil.

Watering in winter is not required, as the colder temperatures cause the rhizomes to shrink and go dormant.

– Light

The Costus Spectabilis mostly prefer to grow in shady spots of the garden, with medium diffused lighting. Some cultivars have acclimated to thrive in higher light levels, even in full sunlight.

Costus Spectabilis prefer shady spots

The ideal lighting conditions for the Yellow Trumpet are morning sun exposure and shade in the afternoon.

While it enjoys the sun, the harsh afternoon exposure can damage the plant and cause leaf burns.

The Yellow Trumpet may not flower if placed in a completely shaded area, although the plant can easily recover once moved to sunnier spots.

– Soil

The Costus Spectabilis requires light, quick-draining soil that can hold a fair amount of moisture. A mix of light sand, rich humus, and loamy soil can keep the plant moist but not overly wet.

The Yellow Trumpet thrives when the soil keeps its rhizome hydrated but not bogged in standing water. The stagnant water can cause the root to develop rot.

– Temperature

The Costus Spectabilis prefers warm tropical environments due to its natural acclimatized habitats. The rhizomatous genotype can tolerate a maximum temperature of 90 F, similar to the hot African temperatures.

The Yellow Trumpet tolerates a minimum of 40 F before it goes dormant or may get frostbitten and perish.

The Costus Spectabilis is perfect for regions where summers are warm and humid.

– Humidity

The Costus Spectabilis is accustomed to environments where humidity levels are high. Its natural habitats ensure that the air moisture levels are constantly present, and the plant does not do well in drier air conditions.

The Yellow Trumpet prefers daytime humidity levels at 60 to 90 percent, while it prefers nighttime air moisture levels at 70 to 90 percent.

Some gardeners prefer to mist the plant to increase the humidity, although a shallow pot of water near the plant can also work.

– Fertilizer

The Costus Spectabilis can grow prolifically on its own without requiring any supplemental feeding. In cultivation, gardeners fertilize the rhizomatous geophyte with weak liquid fertilizers that contain a fair number of micronutrients.

The Yellow Trumpet plants can be heavy feeders during the growing season. Gardeners are advised to feed the plants with diluted liquid fertilizer solutions regularly.

– Rest Period

The Costus Spectabilis has a natural growth cycle that sees the plant thriving during the wetter seasons of the African region and going dormant in the drier seasons. The wetter periods tend to start in April or May and usually end around October.

Costus Spectabilis Natural growth cycle

Once the Yellow Trumpet goes dormant, the rhizomatous geophyte reverts to a thin rhizome that resembles a centipede. The roots die off during this period.

Upon the approach of the wetter seasons, the perfect combination of rainwater and soil warmth encourages the rhizome to plump up, grow foliage, and flower.

In cold climate cultivation, the rhizome should be preferably kept dry indoors and planted again once spring arrives.


The Costus Spectabilis is a rhizomatous geophyte, which means they grow and multiply from underground rhizomes. It can be pretty difficult to find Costus Spectabilis seeds for propagation, as rhizome division is the easiest and most common method of cultivation.

Divided rhizomes can be replanted in new containers. Ideally, containers should be large to anticipate the Yellow Trumpet rhizomes from overcrowding.

The newly-planted rhizomes can be kept warm and moist, although full sun exposure at the stage is not recommended. Once new growth is evident, slowly introduce the plant to sun exposure.

Features of the Costus Spectabilis

– Name Origins

The Costus Spectabilis plant was first documented by Eduard Fenzl, an Austrian botanist, and Karl Mortiz Schumann, a German botanist.

Costus is the name given to a group of perennial herbaceous plants that are under the family Coastaceae. It is often distinguished from the true ginger family by its stems that spiral, which is why this genus is often called spiral gingers.

Other Name

The Costus Spectabilis is also commonly known as the Yellow Trumpet. Spectabilis is Latin for “admirable,” “remarkable,” or “notable.”

– Size

The Costus Spectabilis can grow up to almost a foot wide, with each leaf growing around five inches wide and long. The herbaceous perennial plant is made up of four dark green basal rosette leaves, which are flat. The brilliant yellow flowers rise around two inches from the base of the leaves.

This gorgeous, sunny plant is often cultivated in ornamental gardens for its unique beauty and ease of care.

– Leaves

The Costus Spectabilis produces four large leaves that are fleshy and spread flatly across the ground. This formation is often called a basal rosette, and the leaves are smooth on top with tiny hairs underneath, located along the midrib of the leaf.

Costus Spectabilis produces 4 large leaves

The leaf is edged in a purplish-pink color, and the surface of the abaxial leaf is quite spongy, textured, and white. New leaves are shiny, with a slight golden sheen and red margins. Formed together, the whole plant resembles a floating lily pad that seemingly sprouted from the earth.

– Roots

The Costus Spectabilis is a rhizomatous geophyte, which stores energy and water in an underground storage organ. The roots are covered in light brown crepey sheaths. These scaly coverings are hairy on the lower parts and lengthen to spread below underground to create new plants.

In pots, these offshoots tend to grow out of the drainage holes or coil around the containers. When faced with colder weather, the rhizomatous geophytes shrink into worm-like shapes without any roots.

– Flowers

The Costus Spectabilis produces brilliant yellow blooms with a wrinkled margin. The inflorescence of the Yellow Trumpet is terminal and grows from the center of the basal rosette. The single flower opens and wilts rapidly, although another flower immediately follows the previous one.


These trumpet-like golden flowers can grow up to an average of 3.5 inches across. The labellum of the staminode is large, and the flower of the Costus Spectabilis resembles those of pumpkins.

The flowers are showy and bright yellow, with a thin, soft textured petal. The texture of the flower causes the Yellow Trumpet blooms to shimmer in the sunlight.

The Costus Spectabilis is commonly yellow but sometimes can come in crimson red color. The floral margin can also range from a small trumpet flare to a broad, ruffled edge.

– Habitat

The Costus Spectabilis is a perennial rhizome that belongs to the Coastaceae family, which is a close relation to the ginger family. These tropical plants are normally found in Asia and Africa and Australia and the North and South Americas.

Yellow Trumpet Native in Africa

The Yellow Trumpet is much more common in Africa, where the hot tropical climates of Angola, Ethiopia, Kenya, Mozambique, Uganda, Zambia, and Zimbabwe are its native habitats. The geophyte can even be found growing in shady, sandy soil, among rocks, and even near termite mounds.


What does the Costus Spectabilis symbolize?

The Costus Spectabilis symbolizes beauty and resilience in various cultures worldwide.

What are the medicinal uses of Costus Spectabilis?

Medicinally, Costus Spectabilis is used to treat digestive disorders, skin ailments, and inflammatory conditions.

What is a major disadvantage of Costus Spectabilis?

A major disadvantage of Costus Spectabilis is its potential for causing allergic reactions in some individuals.


The Costus Spectabilis is undeniably a beautiful, brilliant plant that brings a spot of warmth to any garden where the plant is cultivated. The zen-like charm and elegance of its broad leaves echo water lily pods, with the blooms seemingly like the lotus bloom itself.

Let’s review what we’ve learned so far about this golden Yellow Trumpet:

  • The Costus Spectabilis is a rhizomatous geophyte that stores its energy and nutrients underground.
  • The Yellow Trumpet is Nigeria’s national flower and is a relative of the ginger family.
  • The Costus Spectabilis prefers warm tropical climates, although it is also easily cultivated in colder regions under ideal growing situations.
  • The Yellow Trumpet is easy to care for and propagate, as long as the water, temperature, and soil conditions are ideal.

Low-maintenance, regal, and humble, the Yellow Trumpet always brings sunny smiles and joyful moments to anyone who cultivates it!

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