Horti field notes 2: Hydrocotyle sibthorpioides as invasive species

MANILA, Philippines - The mini Hydrocotyle introduced into gardens as ground cover, aquarium plant and bonsai soil cover is becoming a pest in Indonesia. The cute little plant grows horizontally and can cover a wide area in the shortest period of time. The plant survives the worst water logging and dessication. Manual weeding actually helps propagate the plant. There is no way the gardener can get rid of the plant by digging unless the first 3 inches of soil is included. A node or two from the runners will always be left in the soil to start a bigger colony. Mowing the colonies rejuvenates the old plants and new colonies regrow healthier.

Hydrocotyle sibthorpioides can live under full sun, under shade and in bog conditions. The seeds are very small and are spread by ruminants. While growing, the rhizomes can climb over whatever small plants in its path and smother them to death. Even the toughest Flat Grass (incorrectly Frog grass) is no match for H. sibthorpioides.

The invasive species is widespread in the country since it is liked by the gardeners. The danger is when these little monsters stick out of where they are lurking and starts invading vast areas in the landscapes.