Above and below · one kapok
2026
The roots go out, not down.
Everyone draws a tree with roots as deep as its crown is high. Almost no tree grows that way, and the kapok least of all: its roots run wide and shallow, and the planks that rise from them hold up a trunk the height of a church.
A root plate, not a root ball
The kapok’s roots leave the trunk near the surface and run nearly horizontal, ten meters or longer, in the top 40 to 80 centimeters of soil. Excavated in Panama, young trees’ roots reached 20 meters from the trunk, about 1.3 times the radius of the crown. The deepest roots in tropical deciduous forest reach about four meters; the tree above them may be ten times that.
What the buttresses are for
A buttress is the main lateral root thickened upward into a plank, three to eight meters high on an old kapok and a meter or two out, six meters on the Panama giant. They are only a few inches thick. They work like guy ropes and props at once, pulling on the windward side and pushing on the lee, and supply about sixty percent of the tree’s anchorage.
How long a kapok lives
No kapok has been dated by its rings or by carbon. The best-known trees are estimates: at least three hundred years for a Barro Colorado kapok measured by the Smithsonian, about four hundred for the ceiba of Vieques and the Cotton Tree of Freetown, five hundred for the ceiba of Ponce. The tallest verified by laser is Costa Rican, on the Pacific coast.
The Maya planted it at the center of the universe.
To the Maya the ceiba was yaxché, the world tree: its roots in the underworld, its trunk in the world of the living, its branches holding up the heavens. Four ceibas stood at the corners of the world and a fifth at its center. The Taíno called it the daughter of a goddess, and in West Africa it is sacred still. A people who had never dug one up drew it the way this page does, half above the ground and half below.
Four kapoks grow on the estate: two beside the entrance driveway, planted in June 2015, and two in the palm jungle.
What the research says.
The numbers behind the drawing, with where each one comes from.
Four kapoks were planted here in 2015. In 2315 they would be three hundred years old, and only just grown up.
How this was made. The tree is drawn to one scale above and below the ground, from published figures for Ceiba pentandra: the USDA Forest Service silvics sheet (Chinea-Rivera 1990), PROTA, the World Agroforestry database, CIRAD’s plantation growth tables, the Smithsonian’s measurements of the Barro Colorado giant, Sinacore and colleagues’ root excavations in Panama, Crook, Ennos and Banks on buttress mechanics, and Canadell and Jackson on how deep and how shallow forest roots go. “In this garden” follows a watered, open-grown tree in a five-month dry season, which the sources put at 25 to 40 meters; “As a forest giant” follows the wet-forest emergents, 50 to 60 meters. The age at which the buttresses begin, and the shape of the roots past the tenth year, are interpolations between those sources, and no kapok has ever been dated by its rings. Real trees vary with soil, water and luck; this is an illustration, not a forecast.