groundcover
Blue star creeper
Isotoma fluviatilis
Preview: plant data is awaiting horticulturist review. A professional horticulturist hasn't reviewed our plant table yet. Lists still follow fixed rules for zone, sun, pets, deer and invasive status.
Isotoma fluviatilis is a fast-growing semi-evergreen groundcover for gardens in zones 5–9. It grows 1–3 in tall and 1–1.5 ft wide, so plant it 1 ft apart. Give it part sun to part shade and average water. It flowers blue in May to August. In a FloraVista list it usually plays the edge role: a low plant that finishes the front edge. Deer may browse it when other food is short, and it is toxic to dogs and cats. Our rules leave it out of lists in Florida and the Gulf, Texas and the South-Central states and the Desert Southwest, where summer heat, humidity or mild winters hold it back even inside its zone range.
Facts from our plant table
- Botanical name
- Isotoma fluviatilis
- Plant type
- Groundcover, semi evergreen
- Hardiness zones
- 5 to 9
- Sun
- Part sun (4–6 hours); Part shade (2–4 hours)
- Water
- Medium
- Soil
- Moist, well-drained soil; good between stepping stones.
- Mature size
- 1–3 in tall × 1–1.5 ft wide
- Spacing
- 1 ft apart (centre to centre)
- Growth rate
- Fast
- Bloom
- May–Aug · blue
- Roles in a bed
- Edge
- Styles
- cottage, classic
- Deer resistance
- Medium: browsed when deer are hungry
- Pets
- Toxic to dogs and cats. Lobelia relative that may contain irritant alkaloids; no ASPCA entry found. Marked toxic.
- Native to
- Not native to the US (or a garden hybrid)
- Pot size and price
- 4-inch pot, typically $4–$8 (sometimes stocked)
- Plant in
- Spring or Fall
- First-year watering
- Water deeply once or twice a week through the first summer, more in heat; keep the soil evenly moist but not soggy. Established plants need water only in dry spells.
Sources: Missouri Botanical Garden Plant Finder; state extension service fact sheets; ASPCA toxic and non-toxic plant list; Rutgers NJAES deer resistance ratings; state extension service; Invasive Plant Atlas of the United States; state noxious weed and invasive plant lists; US garden-centre and home-improvement retail listings (general knowledge, 2026 estimate). Not yet reviewed by a horticulturist.
Good companions
The plants our list engine most often puts in the same bed as Blue star creeper, across the sun, zone, pet, deer and style combinations it fits.
- Japanese sedge 'Evergold'Carex oshimensis 'Evergold'ornamental grass · zones 5–9
- Lenten roseHelleborus × hybridusperennial · zones 4–9
- Bleeding heartLamprocapnos spectabilisperennial · zones 3–9
- Hairy alumroot 'Caramel'Heuchera villosa 'Caramel'perennial · zones 4–9
- Reblooming azalea 'Encore Autumn Amethyst'Rhododendron 'Conlee'shrub · zones 6–9
- Hardy geranium 'Rozanne'Geranium 'Gerwat' (Rozanne)perennial · zones 5–8
If you can't find it
Plants that do the same job and pass the same rules for the conditions Blue star creeper suits.
- Hens and chicksSempervivum tectorumzones 3–8 · not flagged toxic to pets
- Two-row stonecrop 'Dragon's Blood'Sedum spurium 'Dragon's Blood'zones 4–9 · not flagged toxic to pets
- Creeping thymeThymus serpyllumzones 4–9 · not flagged toxic to pets
- Variegated lilyturf 'Variegata'Liriope muscari 'Variegata'zones 6–10 · not flagged toxic to pets
How this page was made
This page was generated from this plant's record in FloraVista's plant table by fixed rules. The companions and substitutes come from the lists our rules engine composes. No named expert has reviewed this page.
Data status: the plant table is awaiting review by a horticulturist. Check each plant with a local nursery or extension office before you buy.
Sources
- Missouri Botanical Garden Plant Finder, state extension services and the USDA PLANTS database (zones, size, sun, water, bloom, native range)
- ASPCA toxic and non-toxic plant lists (dog and cat toxicity)
- Rutgers NJAES and regional extension deer-resistance ratings
- State noxious-weed and invasive-plant lists and the Invasive Plant Atlas of the US
- Typical US garden-centre listings (pot size and price band)
Generated . How FloraVista chooses plants