Care guides

For most carnivorous plants

• Building an outdoor bog garden for pitcher plants and flytraps

  An outdoor bog is a lined hole filled with peat and sand, with drainage holes partway up the liner so it stays wet without flooding. For Sarracenia the ICPS recommends keeping the water level 7 to 18 cm (3 to 7 in) below the surface. In cold areas, a deep pine-needle mulch added once the plants are dormant carries them through winter.

• Buying carnivorous plants legally and responsibly

  Buy nursery-propagated plants and never take plants or seed from the wild; the US Fish and Wildlife Service asks buyers to purchase only Venus flytraps grown from tissue culture. In North Carolina, taking a wild Venus flytrap or its seed from another person's land or public land with intent to steal is a Class H felony. Three Sarracenia are federally endangered and on CITES Appendix I, while the Venus flytrap and most other Sarracenia and Nepenthes are on Appendix II.

• Carnivorous plant soil: peat, sand, perlite and sphagnum mixes by genus

  The ICPS default for most carnivorous plants is an equal mix of unfertilized sphagnum peat and coarse silica sand with grains of about 1.5 to 2 mm. Potting mix, play sand and builders sand are out. Several groups need something else: Cephalotus a much sandier mix, Mexican butterworts a mix with perlite, and Nepenthes and Heliamphora blends based on long-fiber sphagnum.

• Feeding carnivorous plants, and why fertilizer is risky

  Plants that catch insects on their own need no help, but a plant that is not catching prey should be fed in the traps with live insects or rehydrated dried bloodworms. Do not fertilize the soil of Venus flytraps, sundews or adult Sarracenia: the ICPS warns it can kill flytraps and feeds the fungi behind Sarracenia rhizome rot. Juvenile Sarracenia, Drosera regia, Heliamphora and Cephalotus are the exceptions that can take measured fertilizer.

• Growing carnivorous plants indoors all year

  Indoors, light decides almost everything. Venus flytraps can grow year-round under about 15,000 to 25,000 lux of white LED light for about 14 hours a day, with regular feeding and no terrarium or dormancy. Without grow lights, the ICPS points to Mexican butterworts and many Nepenthes for windowsills. Among Sarracenia, only S. psittacina and S. rosea are recommended for growing under lights all year.

• Light for carnivorous plants: sun, windowsills and LED grow lights

  Venus flytraps, Sarracenia seedlings, most sundews, Cephalotus and Heliamphora need intense light: full sun outdoors, or about 15,000 to 25,000 lux of white LED light indoors for 12 to 16 hours a day. A typical house windowsill does not give a flytrap enough. Nepenthes, butterworts and bladderworts are moderate-light plants at about 8,000 to 15,000 lux.

• Repotting carnivorous plants: when, how and in what

  Repot when a plant grows into the edge of its pot, the soil turns salty or mossy, or new growth fails; the ICPS says a well-kept Venus flytrap needs this about every year. Sarracenia need dividing every three or four years, ideally just as growth starts in spring, and cold temperate sundews are repotted in early spring as their winter buds open.

• Terrariums and humidity: which carnivorous plants need them

  Most carnivorous plants need less humidity than people expect, and the ICPS says Venus flytraps need no terrarium at all. Heliamphora are the main exception: they need an enclosure unless the room's humidity is above 70%. Subtropical sundews, Drosera adelae and its relatives, and seedlings and fresh cuttings also do best with extra humidity.

• Water for carnivorous plants: TDS limits, rainwater and the tray method

  Use rain, distilled or reverse-osmosis water, or tap water only if its total dissolved solids (TDS) are low: the ICPS Venus flytrap guide puts the line at 90 ppm and its seed guide at 80 ppm. Ordinary filters do not remove dissolved salts. Most bog plants stand in a tray of water that is never allowed to dry out, about 1 to 2 cm deep for a flytrap and 4 to 6 cm for a mature Sarracenia.

• Winter dormancy: which carnivorous plants need it and how to provide it

  Sarracenia expect a cool winter rest, and cold temperate sundews and butterworts need real winter cold to survive long term. Venus flytraps outdoors go dormant and must be dormant before a hard freeze, but the ICPS says flytraps kept indoors under strong lights need no dormancy and that refrigerating them is a waste. Subtropical sundews such as Drosera capensis need no rest at all.