The Record
Every care guide sounds certain. They are not all saying the same thing. These are the points where reputable sources genuinely conflict — and where we tell you which way we lean, and why.
Dormancy: ICPS holds that flytraps do not require dormancy indoors given 15,000–25,000 lux for 14 hours plus regular feeding. Barry Rice and every major nursery call it required. We ship 'required' — the ICPS exemption depends on light most growers never reach.
Trap triggering: the 'never touch the traps' rule is directionally right but overstated. Rice notes a trap can close roughly half a dozen times before it stops functioning, because the mechanism is acid growth and the cells can only stretch so far. An exhausted trap still photosynthesises and does not kill the plant.
Tap water ceiling: ICPS permits under 90 ppm, Predatory Plants under 100, Sarracenia Northwest under 50. We ship 50 — the higher figures assume competent flushing and annual repotting.
Division season: ICPS, Rice and Sarracenia Northwest all say late winter to early spring. Plant Delights recommends early fall while roots are actively growing. Default to spring.
Winter trimming: ICPS recommends a fall haircut for plants moved indoors, because of poor air circulation. Plant Delights says leave dead leaves on through winter as insulation and remove in spring. The rule that reconciles them is conditional — outdoors leave until spring, indoors or garage trim in fall.
Shade tolerance: secondary sources widely claim 30–50% shade for purpurea and psittacina. That figure appears on no ICPS, Rice or major-nursery page. What is defensible: these tolerate moderately less light and are the only Sarracenia that succeed indoors. They are not shade plants.
The cool-roots question is the most contested point in the hobby. ICPS, Rice and California Carnivores all treat active root cooling — ice cubes, refrigerated water, chilled benches — as necessary. Sarracenia Northwest calls that a myth and says cool summer nights plus rot-free media are what matter. Both camps agree the failure mode is sustained warm roots; they differ on method. Where nights are cool, the daily minimum does the work growers were attempting with ice cubes.
Media: Sarracenia Northwest goes further and says avoid peat and dead sphagnum entirely in favour of fully mineral mixes, on the grounds that dead organic media is the substrate for the fungal rot that actually kills the plant. That is mechanistically coherent and explains why some warm-climate growers succeed without chillers.
Humidity: ICPS says subtropicals prefer higher humidity than typical houses. Grower reports and Carnivorous Journey say the common species tolerate low humidity fine. The reconciliation is that light, not humidity, drives dew production.
Summer rest: ICPS and the European growers describe a real summer dormancy needing barely-moist media. California Carnivores says it is unnecessary and care is unchanged. Mild-summer climates probably explain the difference.
Gemmae viability: ICPS says gemmae stay dormant and viable for a month or more unplanted. Flísek and Pásek say every day of storage impairs viability and state plainly that the maximum is not known. Sow within days.
Humidity: ICPS holds that acclimated Nepenthes pitcher fine at ordinary household humidity, while most vendors specify 70%+. Both are describing real outcomes — the disagreement is about acclimated plants versus freshly shipped ones.
Standing water: the consensus is no tray at all, but some growers keep lowlanders in a shallow tray successfully in very warm conditions where evaporation is fast. It is not a safe default.
Where the boundaries fall: no source agrees precisely on which species are intermediate rather than highland. N. ventricosa, maxima and sanguinea are placed in both camps depending on who is writing, which is why this group is described by the tolerance band rather than by altitude.
How strict the night drop is: every source agrees it is required for the true ultra-highlanders, but they differ on the marginal species. Growers report N. ventricosa and sanguinea doing well without one, which is precisely why those sit in the intermediate group here.
Whether intense light or cool air is the limiting factor for colour: Carnivero's PPFD figures suggest light, while habitat accounts emphasise the temperature differential. In practice growers who supply both get the colour and those who supply one do not.
Whether the winter rest is obligatory. Most sources treat the succulent phase as a required annual cycle; some growers keep P. gigantea and a few others in carnivorous growth year round under strong light without apparent harm. Nobody disputes that watering a plant which HAS gone succulent will kill it.
Media pH: ICPS notes many Mexican species are limestone plants tolerating alkaline conditions, while much general carnivorous advice insists on acid mixes. The genus is the main exception to the acid rule.
Hibernaculum moisture — see the dormancy note. The honest summary is that drainage decides the answer, not a rule about wetness.
Whether the weedier species are a nuisance. U. subulata and bisquamata colonise other pots and several growers treat them as contaminants rather than as plants; others grow them deliberately for the flowers. Both positions are about the same behaviour.
Whether companion planting is necessary. Most successful accounts keep aquatic Utricularia alongside rushes, sphagnum or other bog plants and credit them with conditioning the water; some growers maintain them in bare tanks with peat filtration alone.
ICPS is the notable dissenter: it holds that flytraps do not require dormancy indoors given very strong light (15,000–25,000 lux, 14 hours) and regular feeding. Barry Rice and every major nursery disagree and call it required. We ship 'required' because the ICPS exemption depends on light levels most growers never reach, and being wrong in that direction kills the plant.
Barry Rice notes coastal-provenance plants seem to need less dormancy than plants from snowy areas — but sellers rarely know a plant's provenance. Carnivorous Plant Nursery's 4–6 months is an outlier; treat it as an upper bound.
Duration varies sharply by species: ICPS gives 6 months for D. rotundifolia and D. anglica, and up to 9 months for D. linearis. Carnivorous Plant Nursery's '45 days at 45°F' is a survival floor, not a target, and is not endorsed by ICPS or Rice.
How wet to keep the hibernaculum. ICPS and European alpine growers keep them damp, on the grounds that these overwinter under snowmelt in habitat; several nurseries advise nearly dry to prevent rot in a pot. The disagreement is really about drainage — a mineral mix tolerates the wet that a peat mix does not.
Where sources conflict we ship the conservative position — the one whose failure mode is a slightly over-cautious grower rather than a dead plant. Being told to give a flytrap dormancy it didn't strictly need costs nothing. Being told to skip it costs the plant.