Hydrocotyle is an herb native to South America. Most species grow only an inch tall, which earned hydrocotyle the nickname "pennywort," but others can grow up to 10 inches tall. This plant is hardy down to USDA zone 6, which means it overwinters in areas where the temperature stays above -10 F. Knowledge of how to plant this herb will add a low-maintenance plant to your landscape.
Fill a seed flat with a mix of half peat and half perlite in early spring. Plant the hydrocotyle seeds 1/2 inch deep and tamp the soil down firmly. Water the seeds deeply.
Place the seed flat in a cold frame, keeping the potting medium moist. This will protect it from the cold and the elements. When the seeds grow large enough to handle transplanting, move them into individual pots.
Care for the seedlings over the winter. Place them in a well-lit area and keep them moist so they grow strong roots.
Find an area outdoors to plant the herb the following spring. Hydrocotyle prefers full sun or light shade and an area that is permanently moist. Bogs or marshes, as well as right on the edges of ponds, are good spots for this plant.
Plant the pennywort at the same height it resided in its pot. If it doesn't naturally have constant moisture, provide it with water each day.