Lobelia niihauensis Plant Care
Lobelia niihauensis St.John
Updated · Sources · How we source care data
Lobelia niihauensis, commonly known as the Niihau lobelia, is a rare species of flowering plant in the bellflower family that is endemic to Hawaii. It is known only from the islands of Oʻahu and Kauaʻi and is thought to be extirpated from Niʻihau.
Every 3–7 days
Full sun to part shade
50–75°F
40–70%
At a glance
How do you care for Lobelia niihauensis?
Water Lobelia niihauensis every 3–7 days, letting the top layer of soil dry out between waterings, and give it full sun to part shade. It prefers temperatures of 50–75°F (10–24°C) and 40–70% humidity. Fertilize it every 6 months during the growing season.
Where Is the Lobelia niihauensis Native To?
What Is the Lobelia niihauensis?
Lobelia niihauensis (Lobelia niihauensis) belongs to the Campanulaceae family within the Lobelia genus. Lobelia niihauensis is native to Hawaii.
Lobelia niihauensis displays a spreading, low-growing perennial growth habit, reaching up to 0.5 ft tall with a spread of approximately 1.5 ft. Lobelia niihauensis produces tubular flowers in shades of blue, purple, pink, or white.
Leaf size: approximately 2 inches.
How Often Should You Water a Lobelia niihauensis?
Lobelia niihauensis requires watering every 3–7 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 3–7 days
Let soil partially dry between waterings
What Light Does the Lobelia niihauensis Need?
Lobelia niihauensis thrives in full sun to part shade.
Light Requirement
Full sun to part shade
What Temperature and Humidity Does the Lobelia niihauensis Prefer?
Lobelia niihauensis grows best at temperatures of 50–75°F. Lobelia niihauensis prefers humidity levels of 40–70%.
Temperature
50–75°F
Humidity
40–70%
What Soil Mix Works Best for a Lobelia niihauensis?
Moist, well-draining soil rich in organic matter. Good drainage is essential for Lobelia niihauensis to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Lobelia niihauensis?
Feed Lobelia niihauensis every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Lobelia niihauensis?
Repot every 1-2 years in spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Lobelia niihauensis?
Lobelia niihauensis can be propagated through seeds, division. Similar propagation techniques also apply to cardinal flower plant care, which shares the same genus.
Is the Lobelia niihauensis Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Lobelia niihauensis, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Lobelia niihauensis?
Lobelia niihauensis is susceptible to aphids, slugs, snails. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Lobelia niihauensis Need?
Lobelia niihauensis grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Lobelia niihauensis is native to Hawaii. In cooler regions, grow Lobelia niihauensis as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Lobelia niihauensis is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Lobelia genus — compare its care with other Lobelia species on PlantoScan.
Lobelia is part of the Campanulaceae plant family — browse all Campanulaceae genera and species.
Lobelia niihauensis thrives in bright light and direct sun — see other bright-light plants.
More Lobelia Species
Other Lobelia species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Lobelia niihauensis St.John, family Campanulaceae (first published in Occas. Pap. Bernice Pauahi Bishop Mus. 9(14): 9 (1931)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Lobelia niihauensis, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Hardiness zone: USDA Zone 12a, calculated from the plant's minimum temperature.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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