Green cabomba

Cabomba caroliniana

Also known as Carolina fanwort, Green cabomba, Fanwort, Cabomba, Washington grass

FreshwaterStemCuttingsSide shoots

Invasive. Invasive and regulated in parts of the US (banned for sale in some states) and elsewhere. Never release into the wild; dispose of in the trash.

Green cabomba (Cabomba caroliniana) — Leslie J. Mehrhoff, University of Connecticut, Bugwood.org · CC BY 3.0

Care at a glance

Light: High light
CO2: CO₂ beneficial
Growth rate: Fast
Placement: Background
Type: Stem
Temperature: 64–82°F (18–28°C)
pH: 6.0–7.5
Hardness: 2–15 dGH
Max height: 23.6 in (60 cm)
Spread: 3.1 in (8 cm)
Nutrient uptake: Root + water column
Growth region: Submersed
Difficulty: Medium
Origin: Southeastern North America and subtropical South America (Brazil, Argentina)
Family: Cabombaceae

Overview

A fast, feathery background stem planted in thick groups, weighted or anchored because the brittle stems uproot easily. It needs strong light to stay dense; under weak light it goes leggy and the lower stems strip bare. CO2 and good iron dosing keep it lush, and it dislikes being shaded or disturbed, so it suits stable, high-flow tanks. Important: this plant is a regulated noxious weed in many places, so never release trimmings or old plants into natural water, and check local rules before keeping it.

In the wild

Cabomba caroliniana is native to the southeastern United States (Florida, the Gulf states and the Carolinas) and to subtropical South America in Brazil and Argentina, growing rooted in slow streams, ponds and ditches with its finely divided fan leaves fully submersed. It spreads readily from stem fragments, which is exactly how it has escaped into waterways well outside its native range. It is essentially an obligate underwater plant and does poorly grown emersed.

Good to know

It belongs to Cabombaceae, a small family of aquatic plants closely tied to the water lilies. The submersed leaves are oppositely arranged and split into a fan of fine segments, while the floating leaves it produces at flowering are small and shield-shaped. Legally it is a serious problem species: Cabomba caroliniana is listed as a noxious or prohibited aquatic weed in numerous US states (sale is banned in Washington and it is restricted in states including CA, CT, ME, MA, MI, NH, NY, VT and WI) and is invasive across parts of Europe, Asia, Australia and Canada.

Did you know

Did you know its weediness has earned it the nickname Washington grass, even though it is banned for sale in Washington State. A single broken stem fragment can root and start a whole new infestation, which is why it is so tightly regulated.