Hydrocotyle vulgaris, or Water Pennywort (Marsh Pennywort in the UK), is a small creeping perennial herb native to N. Africa, Europe and west to the Caspian region. The stems either float in water or creep, rooting at each node. The leaves are peltate, orbicular to 2 inches (5 cm) across. They are great plants for bog terraria and for under propagation benches in the greenhouse. They are easy to culture and are hardy in USDA zones 6-10.
Blooming: In the greenhouse, the plants flower in late summer. The very small greenish white flowers are on 2-5 flowered umbels. Not particularly showy.
Culture: Hydrocotyle vulgaris will grow in full sun to full shade in a moist to wet soil mix. In the greenhouse, we use a soil mix consisting of 1 part peat moss to 1 part loam to 2 parts sand. Our plants are grown in terraria and under the misting bench in the greenhouse. The plants need to be kept moist at all times and when grown in the terrarium they can have up to 1 inch (2.5 cm) of water standing on them. They are very vigorous growers and need to be thinned out periodically. If grown in the landscape, their best use is around water features. During the winter months in the greenhouse, the plants in terraria are allowed to go dormant by dropping temperature to around 40°F (5°C). In the landscape, plants will die back to soil level.
Propagation: Hydrocotyle vulgaris is propagated from division of the creeping stem and from seed.
Hydrocotyle vulgaris was featured as Plant of the Week August 12-18, 2005.
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.