Silk Floss Tree (Ceiba speciosa)

Silk floss tree (Ceiba speciosa), or floss silk tree, whichever the correct name, this specimen has superb showy qualities. This deciduous tree is a true stunner and has the potential to attain a height of over 50 feet (15 cm.) with an equal spread. Growing silk floss trees are found in their native tropics of Brazil and Argentina.

I. Appearance and Characteristics

Ceiba speciosa, the floss silk tree (formerly Chorisia speciosa), is a species of deciduous tree that is native to the tropical and subtropical forests of South America. It has several local common names, such as palo borracho (in Spanish literally “drunken stick”), or árbol del puente, samu’ũ (in Guarani), or paineira (in Brazilian Portuguese). In Bolivia, it is called toborochi, meaning “tree of refuge” or “sheltering tree”. In the USA it often is called the silk floss tree. It belongs to the same family as the baobab; the species Bombax ceiba; and other kapok trees. Another tree of the same genus, Ceiba chodatii, is often referred to by the same common names.

The natural habitat of the floss silk tree is in the northeast of Argentina, east of Bolivia, Paraguay, Uruguay, and southern Brazil. It is resistant to drought and moderate cold. It grows fast in spurts when water is abundant, and sometimes reaches more than 25 metres (82 ft) in height. Its trunk is bottle-shaped, generally bulging in its lower third, measuring up to 2 metres (7 ft) in girth. The trunk is studded with thick, sharp conical prickles that deter wild animals from climbing the trees. In younger trees, the trunk is green due to its high chlorophyll content, which makes it capable of performing photosynthesis when leaves are absent; with age it turns to gray.

The branches tend to be horizontal and also are covered with prickles. The leaves are composed of five to seven long leaflets. The flowers are creamy-whitish in the center and pink toward the tips of their five petals. They measure 10 to 15 centimetres (4 to 6 in) in diameter and their shape is superficially similar to hibiscus flowers. Their nectar is known to attract insect pollinators and hummingbirds.

C. speciosa flowers are in bloom between February and May (in its native Southern Hemisphere), but it may bloom at other times of the year, even as late as November in Florida. The flowers of the related C. chodatii are similar in form and size, but their color goes from creamy white centers to yellow tips. As a deciduous tree, it is completely bare of leaves and flowers during the winter months, especially when growing outside of its native South American habitat.

The fruits are lignous ovoid capsules, 20 centimetres (8 in) long, which contain bean-sized black seeds surrounded by a mass of fibrous, fluffy matter reminiscent of cotton or silk.

II. How to Grow and Care

Sunlight

Floss silk tree flourishes best in full sun conditions, where it receives at least 6-8 hours of direct light daily, fostering vigorous growth and prolific flowering. When grown outside its optimal light regime, floss silk tree demonstrates partial sun tolerance but may exhibit subdued growth and fewer blooms. Its adaptability includes the potential to adjust leaf orientation to optimize light absorption. Outdoors, floss silk tree should be planted in open areas to ensure ample light exposure. If positioned indoors, it should be near large, south-facing windows to emulate its natural preferences for robust health and flower production.

Watering

Originating from the tropical climates of South America, floss silk tree is accustomed to a balance of moisture and periods of dryness. This species thrives with moderate humidity and has adapted to withstand short droughts. In cultivation, it benefits from watering once every 1-2 weeks, ensuring the soil partially dries between sessions. Typically grown outdoors due to its size and ornamental value, floss silk tree is an impressive deciduous tree that responds well to seasonal rainfall patterns, shedding leaves in response to water stress or cooler temperatures.

Fertilizing

For healthy growth, floss silk tree benefits from balanced nutrition fertilizers. Spring to summer, monthly application ensures robust flowering, with a reduced frequency as dormancy approaches in fall. Use manufacturer’s suggested quantity, avoiding over-fertilization to prevent root damage. Seasonal adjustments—increased for active growth and reduced in winter—are vital. Apply during watering for optimal uptake. Novices and experts can achieve striking floss silk tree vitality with consistent, mindful nourishment.

Propagation

Floss silk tree can be propagated in autumn or winter. The preferred methods include hardwood cuttings, layering (air), and sowing seeds. Propagation difficulty varies, but signs of successful propagation include root development and the emergence of new shoots. Key propagation-related tips include using sterile equipment and ensuring proper drainage.

Transplanting

The ideal season to transplant floss silk tree is from early to mid-summer, as warmer temperatures encourage strong root growth. Choose a well-draining location with full sun exposure. Gently loosen the root ball when transplanting to promote optimal growth.

Repotting

Repot floss silk tree every 2-3 years to accommodate its robust growth. Best done in spring to sync with growth cycles. Choose a large, sturdy container to support its size and prevent tipping. Post-repotting, ensure ample sunlight and moderate watering—floss silk tree tolerates drought but thrives with care. A spacious pot and consistent care will keep floss silk tree flourishing.

III. Uses and Benefits

The “cotton” inside the capsules, although not so good quality as that of the kapok tree, has been used as stuffing (density = 0.27 g/cm3). The wood can be used to make canoes, as wood pulp, and to make paper. The bark has been used to make ropes. From the seeds, it is possible to obtain vegetable oil (both edible and industrially useful).

The floss silk tree is cultivated mostly for ornamental purposes. Outside of private gardens around the world, it is often planted along urban streets in subtropical areas such as in Spain, South Africa, Australia, northern New Zealand, and the southern USA, although its prickled trunks and limbs require establishing safety buffer zones around the tree in order to protect people and domesticated animals.

Ceiba speciosa is added to some versions of the hallucinogenic drink Ayahuasca.