Nanu Plant Care

Gardenia brighamii H.Mann

Updated · Sources · How we source care data

Gardenia brighamii is a species of flowering plant in the coffee family, Rubiaceae. It is sometimes referred to by the common names nānū, naʻu, or forest gardenia, and is endemic to Hawaii.

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Water

Every 7–14 days

Light

Bright indirect light

Temp

65–75°F

Humidity

50–70%

At a glance

How do you care for Nanu?

Plant Nanu in bright indirect light (USDA zones 13b) and water a young shrub every 7–14 days until it is established. It tolerates temperatures of 65–75°F (18–24°C). Fertilize it every 6 months during the growing season.

Where Is the Nanu Native To?

Native range1 country

What Is the Nanu?

Nanu (Gardenia brighamii) belongs to the Rubiaceae family within the Gardenia genus. Nanu is native to Hawaii.

Nanu displays a compact, evergreen shrub growth habit, reaching up to 4 ft tall with a spread of approximately 4 ft. Nanu produces fragrant, white, waxy blooms.

Leaf size: approximately 4 inches.

How Often Should You Water a Nanu?

Water a young or newly planted Nanu every 7–14 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established shrubs mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Watering Frequency

Every 7–14 days

Until established; then in dry spells

What Light Does the Nanu Need?

Nanu thrives in bright indirect light. Avoid placing Nanu in direct, harsh sunlight for extended periods, as this can scorch the foliage.

Light Requirement

Bright indirect light

What Temperature and Humidity Does the Nanu Prefer?

Gardenia brighamii tolerates temperatures of 65–75°F. Nanu prefers humidity levels of 50–70%. A pebble tray or humidifier helps maintain adequate moisture around the plant.

Temperature

65–75°F

Humidity

50–70%

What Soil Mix Works Best for a Nanu?

Well-draining, acidic soil mix with added peat moss and sand. Good drainage is essential for Nanu to prevent waterlogging, which leads to root rot and fungal issues.

How Often Should You Fertilize a Nanu?

Feed Nanu every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established shrubs in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

Fertilizing

Every 6 months

During the growing season

The PlantoScan app can remind you when to water and when to fertilize each plant.

Where Should You Plant a Nanu?

Choose a spot with bright indirect light and well-draining, acidic soil mix with added peat moss and sand. Avoid low spots where water collects after rain.

Nanu is suited to USDA Zone 13b.

Plant container-grown or balled-and-burlapped shrubs in spring or early autumn, setting the root flare at soil level, and water well after planting.

How Far Apart Should You Plant a Nanu?

Nanu can spread to about 4 ft (1.2 m) and reach about 4 ft (1 m) tall. Space plants about 4 ft (1.2 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the plant spacing calculator.

How Do You Prune a Nanu?

Prune Nanu while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the shrub in one year.

How Do You Care for a Nanu in Winter?

Nanu is frost-tender (hardy to USDA zone 13). In colder areas grow it in a container and move it to a bright, frost-free place before the first frost.

How Do You Propagate a Nanu?

Nanu can be propagated through softwood cuttings, air layering, seeds. Similar propagation techniques also apply to gardenia plant care, which shares the same genus.

Is the Nanu Toxic to Pets and Children?

Pet safety not verified

The ASPCA does not list Nanu, 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 Nanu?

Nanu is susceptible to aphids, whiteflies, scale insects. 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 Nanu Need?

Nanu grows outdoors in USDA Zone 13b. It survives winters down to planting zone 13b. Nanu is native to Hawaii. In cooler regions, grow Nanu as a houseplant or bring it indoors before the first frost.

Hardiness Zone

Zone 13b

Keep exploring plants

Nanu 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 Gardenia genus — compare its care with other Gardenia species on PlantoScan.

Gardenia is part of the Rubiaceae plant family — browse all Rubiaceae genera and species.

Nanu thrives in bright light and direct sun — see other bright-light plants.

More Gardenia Species

Other Gardenia species in PlantoScan's care catalogue share similar watering, light, and soil preferences:

Sources

  • Scientific name & taxonomy: Gardenia brighamii H.Mann, family Rubiaceae (first published in Proc. Amer. Acad. Arts 7: 171 (1867)) — World Flora Online record, IPNI name record.
  • Pet toxicity: Pet safety not verified: the ASPCA does not list Nanu, 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 13b, 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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