King Henry Venus flytrap (King Henry flytrap) care

Light

King Henry Venus flytrap needs sun on the leaves, not just bright ambient room light. Requires 6+ hours of direct sun daily to develop the light reddening on its large traps and to sustain its vigorous growth rate. Younger plants show the deepest red colouring. Outdoor summer placement or a south-facing window is ideal; high-output LED grow lights work indoors. A south or west-facing windowsill in the northern hemisphere is the default; anywhere else, expect the plant to stretch and pale out within a season.

Watering

Water king henry venus flytrap continuously moist via tray method; barely damp in winter. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Keep the pot in 2–4 cm of distilled, rainwater, or RO water year-round during the growing season. Reduce to barely moist during dormancy. Deeper pots recommended for King Henry — they accommodate its extensive root system and encourage larger trap development.

Soil and pot

King Henry Venus flytrap grows best in nutrient-poor acidic carnivore mix. A 1:1 blend of long-fibre sphagnum moss and perlite, or pure sphagnum, in a deep pot (12–15 cm) to support its substantial root system. No added nutrients. Repot annually in spring; the cultivar frequently produces clumps from its tissue-culture origins that can be divided at this time. 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

King Henry Venus flytrap sits happiest at around 50–80% humidity and 5–35°C (growing season 18–30°C; dormancy 2–10°C) (41–95°F (growing season 64–86°F; dormancy 36–50°F)). Handles average household humidity well when tray-watered. Prefers 60–80% for optimum growth. Its large traps transpire more than smaller cultivars, so slightly higher humidity helps in heated indoor environments. If you keep the room above 5–35°C (growing season 18–30°C; dormancy 2–10°C) 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 king henry venus flytrap sparingly. No soil fertiliser. With its large trap size, King Henry is highly effective at catching insects on its own. Indoors, supplement with freeze-dried bloodworms or small crickets — one per trap every 4–6 weeks. Deeper pots provide additional trace minerals from media decomposition, reducing feeding needs slightly. 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 king henry venus flytrap in the Growli community. Each is annotated with the most common cause so you know where to start.

• Clumping and crowding in pot — King Henry frequently produces multiple crowns from its tissue-culture origins. When the clump fills the pot, the largest traps shrink as resources are divided. Divide clumps in early spring during dormancy break, ensuring each division has several white roots.
• Smaller-than-expected traps — Large traps require deep pots — roots need room to grow. Use containers at least 12–15 cm deep. Insufficient direct sun and inadequate insect feeding also limit trap size. Ensure 6+ hours of direct sun and regular insect feeding during the growing season.
• Post-flowering decline — King Henry matures quickly and flowers within two growing seasons. Flowering is energetically costly — pinch flower stalks off at the base unless deliberately saving seed. Unpinched flowers can weaken the parent rosette significantly.

Propagation

Division of naturally formed clumps in spring (most reliable method, preserves cultivar traits); leaf-pullings on damp sphagnum at 20–25°C. Seeds do not produce true-to-type King Henry offspring — only division maintains the giant-trap characteristic. 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

King Henry Venus flytrap is pet-safe. ASPCA lists Dionaea muscipula (Venus fly trap) as non-toxic to cats, dogs, and horses. No toxic principles are present in this cultivar. 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.

King Henry Venus flytrap deep-dive guides

Every aspect of king henry venus flytrap care, each with its own calibrated guide:

• King Henry Venus flytrap watering schedule
• King Henry Venus flytrap light requirements
• Best soil mix for king henry venus flytrap
• King Henry Venus flytrap fertilizing guide
• When to repot king henry venus flytrap
• How to propagate king henry venus flytrap
• King Henry Venus flytrap growth rate & size
• King Henry Venus flytrap cold hardiness
• King Henry Venus flytrap temperature & humidity
• Is king henry venus flytrap toxic to cats & dogs?
• Is king henry venus flytrap toxic to cats?
• Is king henry venus flytrap toxic to dogs?

Featured in these plant shortlists

King Henry Venus flytrap qualifies for 10 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best pet-safe houseplants — Houseplants the ASPCA lists as non-toxic to cats and dogs — every one verified against the ASPCA toxic and non-toxic plant list.
• Best humidity-loving houseplants — Houseplants that thrive in a bathroom, kitchen, or by a humidifier — selected by documented humidity preference.
• Best pet-safe plants for bright light — Non-toxic to cats and dogs and happy in a bright, sunny spot — safe plants for your best-lit windowsill.
• Best small & tabletop houseplants — Compact houseplants that stay under about 40 cm — desk, shelf and windowsill plants that never outgrow a small space.
• 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 houseplants for a cool room — Houseplants that tolerate cool conditions down to about 10°C — for an unheated spare room, hallway, porch or a home kept cool.
• Best fast-growing houseplants — Houseplants documented as fast or vigorous growers — quick to fill a pot, cover a pole or trail down a shelf.
• Best cat-safe plants — Houseplants the ASPCA lists as non-toxic to cats (and dogs) — safe greenery for a home with a curious cat.
• Best dog-safe plants — Houseplants the ASPCA lists as non-toxic to dogs (and cats) — safe greenery for a home with a curious dog.
• Best small pet-safe plants — Compact, tabletop houseplants that are also ASPCA non-toxic to cats and dogs — safe greenery for a desk or shelf.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

King Henry Venus flytrap is also known as King Henry Venus flytrap, King Henry flytrap, and Giant Venus flytrap.

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