Blue Waterhyssop
Bacopa caroliniana
Last reviewed: October 2026
Bacopa caroliniana, or blue waterhyssop, grows in shallow ponds, ditches, and marshy shorelines across the Southeast, producing small blue flowers from March through November in sunny, consistently wet sites.
Toxicity unknown
Blue Waterhyssop (Bacopa caroliniana) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
full sun
Water
high
Size
12"–36" H × 12"–36" W
Bloom
May, Jun, Jul, Aug, Sep
Native to
AL, FL, GA, LA and 7 more states
Pollinators
butterflies, moths
Before you buy
Your city may pay you to plant this
Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 460 programs across 44 states, each with a link to the provider and the date we last checked it.
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Blue Waterhyssop is a moisture-loving perennial that thrives in wet soils and boggy areas. It produces small blue flowers from spring through fall and maintains a compact, spreading form. This plant is ideal for rain gardens, pond edges, or areas with consistent moisture.
Growing Blue Waterhyssop
Grow Blue Waterhyssop in full sun and high water. Mature plants reach 12 to 36 inches tall and spread 12 to 36 inches wide. Expect low maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Blue Waterhyssop is an HOA-friendly choice. Maintenance level: low. Tidiness: 2 out of 5.
Works well in: front yard, foundation, street edge, mid zone.
Wildlife value
The long blooming season provides nectar for butterflies and moths from spring through late fall. Its dense growth habit also offers shelter for small wildlife.
Common questions
- How much light does Bacopa caroliniana need?
- Bacopa caroliniana grows best in full sun to part sun. It tolerates some part shade but flowers most heavily with more direct light.
- How wet does the soil need to be for blue waterhyssop?
- This plant prefers consistently high moisture, growing well in saturated soil or shallow standing water such as pond edges and ditches.
- When does Bacopa caroliniana bloom?
- Blue waterhyssop generally flowers from March through November, with small blue blooms appearing along creeping stems throughout the warm season.
- What pollinators visit Bacopa caroliniana flowers?
- Butterflies and moths are commonly observed visiting the blue flowers of this wetland plant.
- Is Blue Waterhyssop HOA-friendly?
- Blue Waterhyssop is generally an HOA-friendly choice in the right placement, with low maintenance.
These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.
Native range data from the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
If something looks wrong
Common plant problems, and what to check first
These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.
- It is dying right after planting
- Leaves turning yellow
- Wilting even though I watered it
- Brown crispy leaf tips
- Bugs on the plant
Ready to grow Blue Waterhyssop? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.