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Bacopa spp.
water hyssop
Pantropical and warm-temperate wetlands
Overview
Bacopa spp. is a genus of creeping, mat-forming aquatic and wetland herbs in the family Plantaginaceae, with roughly 70-100 species spread through warm and tropical regions. Stems are prostrate to trailing, rooting at the nodes, and form mats 2-6 inches (5-15 cm) high that spread 12-24 inches (30-60 cm) or more across. Leaves are opposite, small, 0.2-1 inch (5-25 mm) long, fleshy or slightly succulent, and rounded to spoon-shaped; the foliage of B. caroliniana smells of lemon when crushed. Solitary flowers, 0.2-0.5 inch (5-12 mm) across, are five-lobed and white, pale blue, or pink, borne in the leaf axils. Most species are evergreen in frost-free climates and die back where winters are cold. B. monnieri is grown as a medicinal herb and aquarium plant, while B. caroliniana is a common aquarium and pond plant. Plants root readily from stem fragments and can spread quickly in standing water, becoming weedy in warm regions. Growth is rapid in warm, wet conditions and stalls in cold or dry soil.
Native Range
The genus is widespread in tropical and warm-temperate wetlands worldwide, with B. monnieri ranging across India, Asia, Africa, Australia, and the Americas, and B. caroliniana native to the southeastern United States. Plants grow in marshes, pond margins, ditches, and slow streams, in shallow water or saturated mud, from sea level to low elevations.Suggested Uses
Grown as a groundcover for bog gardens and pond margins, as a submerged or marginal aquarium plant, and as a trailing plant in water features, spaced 8-12 inches (20-30 cm) apart. B. monnieri is also cultivated as a medicinal herb. The spreading habit suits shallow water edges but can crowd small ponds.How to Identify
Appearance
Size & Dimensions
Height2" - 6"
Width/Spread1' - 2'
Bloom Information
Flowering occurs through the warm months, from late spring to early autumn in temperate regions and nearly year-round in the tropics. Individual flowers last a few days, with new flowers opening continuously over many weeks. Bloom is heaviest in full sun and warm water.
Detailed Descriptions
Flower Description
white, pale blue, or pinkFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 4-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Plants grow in full sun to partial shade in constantly wet soil, shallow water, or submerged in aquariums, and will not tolerate drying out. Warm conditions of 70-85 F (21-29 C) suit active growth, which slows or stops below about 60 F (16 C). In ponds and aquariums, plants root in mud or substrate and also float as fragments. Plants are frost-tender and die back or rot where water freezes, though B. monnieri survives mild winters in zones 8 and warmer. Algae competition and snails are minor problems in cultivation. Stems are thinned or trimmed to keep mats from overgrowing small water features.Pruning
Trim trailing stems through the growing season to keep mats within bounds and to remove yellowed or rotting growth. Cut fragments root readily and can be replanted to fill gaps. No seasonal cutback is needed in frost-free climates, where growth continues year-round.Pruning Schedule
springsummer
Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons