Canna 'Red King Humbert' (Red King Humbert canna) care

Light

Aim for at least 4-6 hours of direct sun on the leaves. Full sun enhances the deep bronze-purple leaf colour and maximises flowering. At least 6 hours of direct sunlight daily is necessary for strong performance. If your only bright window faces south, that's perfect for canna 'red king humbert' — same window any aroid would fry on.

Watering

Watering canna 'red king humbert': water deeply 2-3 times per week in summer; reduce once foliage begins to die back in autumn. The number that matters isn't the day of the week — it's how dry the top 2-3 cm of the pot feels. A finger in the soil tells you more than a watering app. After every watering, tip the saucer. A thirsty plant in full growth. Consistent moisture throughout the growing season supports heavy leaf production and repeat flowering. In containers, check soil moisture daily in hot weather.

Soil and pot

Canna 'Red King Humbert' grows best in rich, fertile, moisture-retentive loam. Dig in well-rotted manure or compost generously before planting. Cannas are heavy feeders and need a rich growing medium for their full potential. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Canna 'Red King Humbert' sits happiest at around 50-80% humidity and 15-35°C (59-95°F). Prefers higher humidity commensurate with its tropical origins. Adequate moisture in both soil and air prevents spider mite infestations on the large leaves. If you keep the room above 15 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed canna 'red king humbert' sparingly. Feed fortnightly with a high-potassium liquid fertiliser throughout the growing season. The large plant mass requires consistent nutrition to sustain growth and flowering over summer. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on canna 'red king humbert' in the Growli community. Each is annotated with the most common cause so you know where to start.

• Canna leaf roller — Caterpillar larvae roll leaves and feed inside. Remove manually or apply Bacillus thuringiensis where infestations are severe.
• Spider mites — Hot, dry conditions encourage spider mite colonies on the underside of leaves. Increase humidity and wash foliage to dislodge mites.
• Frost damage / overwintering — Not frost hardy. Lift rhizomes after the first autumn frost and store in barely moist compost in a frost-free location over winter.
• Viral mosaic — Mosaic-patterned, distorted leaves indicate canna virus. Remove and destroy affected plants; buy from virus-indexed suppliers.
• Bacterial rot on rhizomes — Damaged or wet rhizomes in storage can develop bacterial rot. Inspect stored rhizomes regularly over winter and remove affected portions.

Companion plants

Canna 'Red King Humbert' pairs well with Canna 'Tropicanna', Dahlia 'Fascination', Ricinus communis 'Carmencita', and Musa basjoo. These are species with similar light and water needs, so you can group them in the same room or on the same shelf and water as a batch.

Propagation

Divide rhizomes in spring, ensuring at least one growing point per section. Start in heated pots under glass in late winter for an early start and plant out after frost risk has passed. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Canna 'Red King Humbert' is mildly toxic to pets. The ASPCA lists Canna generalis as non-toxic to dogs and cats. Not individually listed as safe for horses. Ingestion of large quantities of any canna plant may cause mild gastrointestinal upset, so supervision around pets is recommended. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Canna 'Red King Humbert' deep-dive guides

Every aspect of canna 'red king humbert' care, each with its own calibrated guide:

• Common canna 'red king humbert' problems & fixes
• Canna 'Red King Humbert' watering schedule
• Canna 'Red King Humbert' light requirements
• Best soil mix for canna 'red king humbert'
• Canna 'Red King Humbert' fertilizing guide
• When to repot canna 'red king humbert'
• How to propagate canna 'red king humbert'
• How to prune canna 'red king humbert'
• What's eating my canna 'red king humbert'?
• Canna 'Red King Humbert' growth rate & size
• Canna 'Red King Humbert' cold hardiness
• Canna 'Red King Humbert' temperature & humidity
• Is canna 'red king humbert' toxic to cats & dogs?
• Is canna 'red king humbert' toxic to cats?
• Is canna 'red king humbert' toxic to dogs?
• All 20 Canna varieties
• Getting canna 'red king humbert' to bloom

Featured in these plant shortlists

Canna 'Red King Humbert' qualifies for 4 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best humidity-loving houseplants — Houseplants that thrive in a bathroom, kitchen, or by a humidifier — selected by documented humidity preference.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best houseplants for full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
• Best fast-growing houseplants — Houseplants documented as fast or vigorous growers — quick to fill a pot, cover a pole or trail down a shelf.
• Browse all 30 plant shortlists — pet-safe, low-light, drought-tolerant and more

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Canna 'Red King Humbert' is also known as Red King Humbert canna, Canna lily, and Humbert's canna.

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