Ludwigia sedoides: The Mosaic Rosette Water Plant

Scientific Identity

Ludwigia sedoides is a floating aquatic plant in the family Onagraceae, native to South America (Brazil). It is commonly known as the mosaic plant or rosette-leaf plant. Its small, diamond-shaped leaves arrange themselves on the water's surface in a symmetrical rosette/mosaic pattern, giving it a natural, ornamental look in ponds. In summer, small bright yellow flowers can bloom from the center of the rosette.

Permaculture Value

Ludwigia sedoides partially shades the water's surface, which can help reduce algae growth, and the gaps between rosettes provide a micro-habitat for small aquatic insects. Unlike water hyacinth, it doesn't show an aggressive spreading tendency; it's considered a relatively slower-growing, easier-to-control species, making it a well-behaved ornamental addition to a pond.

Medicinal/Edible Properties

Ludwigia sedoides has no widely known food or medicinal use; it is primarily grown as an ornamental plant.

How to Grow

It needs warm, sunny, still water; being of tropical origin, it is not cold-hardy and generally begins to suffer below 10°C, dying off completely with frost. In temperate climates it cannot be left in an outdoor pond over winter. There are two options: bring it indoors in autumn to overwinter in a lit container or aquarium, or treat it as an annual and re-source it each spring. With plenty of sun and a steady water level, it multiplies quickly in summer and forms a lush rosette.

From the Garden

We haven't overwintered this plant yet; as it stands, we don't think it can survive the winter months in the outdoor pond. Our plan for this coming autumn is to bring part of it indoors to overwinter, while letting the rest take its natural course and reassessing in spring. Its mosaic-patterned rosette leaves are one of the most eye-catching details in the pond.