Dormancy is the part of carnivorous plant care that confuses growers most, and the sources do not always agree. Pick your plant, your hemisphere and where it grows, and add the average high and low of your coldest month. The checker tells you whether a winter rest is needed, roughly when and how long it lasts, whether your climate can provide it, and where the International Carnivorous Plant Society (ICPS), Barry Rice’s Carnivorous Plant FAQ and the nursery Sarracenia Northwest differ.
How the Checker Decides
For the climate test it uses Barry Rice’s description of a suitable “chilly” winter: daily highs not much warmer than 75 °F (24 °C), and nights that rarely, if ever, drop below 32 °F (0 °C). If your coldest month’s highs are clearly above that, the checker treats your winter as too warm for a natural rest. If your lows fall below freezing, it shows what the sources say about frost for your plant.
For timing, Rice gives Venus flytraps and Sarracenia a cool dormancy of about three months. In Rice’s temperature table for Wilmington, North Carolina, in the flytrap’s home range, the coolest months are December, January and February, with mean temperatures of 45 to 49 °F (7 to 9 °C). In the Southern Hemisphere the checker shifts this by six months, to June to August.
What Each Plant Needs
| Plant | Winter rest | Length | Source |
|---|---|---|---|
| Venus flytrap | Required each winter (Sarracenia Northwest, Rice); not required indoors under lights (ICPS) | About three months | Sarracenia Northwest, Rice, ICPS |
| Sarracenia | Required each winter | About three months | Sarracenia Northwest, Rice |
| Darlingtonia | Slows or stops growth | Not given | Rice, ICPS |
| Temperate sundews | Needs a definite winter, rests as winter buds | About six months; up to nine for northern D. intermedia | ICPS |
| Temperate butterworts | Forms winter buds at the start of autumn; needs cold winters | Not given | ICPS |
| Cephalotus | Cool winter rest (Sarracenia Northwest); “no winter dormancy” (California Carnivores) | About three months | Sarracenia Northwest, California Carnivores |
| Mexican butterworts | Cooler, drier succulent phase driven by day length, not cold | Winter to early spring | ICPS |
| Nepenthes | None | None | Rice |
Where the Sources Differ
Do flytraps need dormancy? Sarracenia Northwest says flytraps require a winter dormancy every year, and Rice tells beginners to give one. The ICPS says they do not need dormancy to live long term indoors under lights, only if they will face freezing temperatures outside, and calls putting an indoor plant in the refrigerator a waste.
Can flytraps freeze? Rice tells beginners not to let them freeze. The ICPS says fully dormant plants survive being frozen solid for a week if protected from drying out, and Sarracenia Northwest says they tolerate frost and freezing, with protection in prolonged or severe freezes.
Dark storage. Rice warns that a flytrap in a dark basement, garage or closet will die unless it is in a deep refrigerator dormancy. The ICPS, writing about Sarracenia in very cold areas, lists basements and unheated garages among places they can overwinter, as long as they stay cool to cold.
If You Live in the Tropics
For flytraps, Rice suggests the refrigerator as probably the best method for people in the tropics: the plant in a sealed bag in the fridge, not the freezer, with the soil kept moist, until spring. The ICPS alternative is to grow flytraps indoors under lights and skip dormancy. The sources used for this tool give no tropical method for Sarracenia or temperate sundews and butterworts. Nepenthes, Rice notes, can be grown all year without a rest.
Related Guides
- Venus flytrap dormancy
- Sarracenia dormancy
- Sundew dormancy
- Butterwort dormancy
- Cephalotus winter rest
- Temperature and humidity checker
Sources
- Barry Rice, The Carnivorous Plant FAQ, Winter dormancy? Huh? What? [sarracenia.com/faq/faq2360.html]
- Barry Rice, The Carnivorous Plant FAQ, Dormancy tricks that may work [sarracenia.com/faq/faq2380.html]
- Barry Rice, The Carnivorous Plant FAQ, Should a plant bought in winter be forced into dormancy? [sarracenia.com/faq/faq2420.html]
- Barry Rice, The Carnivorous Plant FAQ, About dormancy requirements [sarracenia.com/faq/faq3480.html]
- International Carnivorous Plant Society, Growing Dionaea [carnivorousplants.org/grow/guides/Dionaea]
- International Carnivorous Plant Society, Growing Sarracenia [carnivorousplants.org/grow/guides/Sarracenia]
- International Carnivorous Plant Society, Growing Darlingtonia [carnivorousplants.org/grow/guides/Darlingtonia]
- International Carnivorous Plant Society, Growing cold temperate Drosera [carnivorousplants.org/grow/guides/ColdTemperateDrosera]
- International Carnivorous Plant Society, Growing temperate Pinguicula [carnivorousplants.org/grow/guides/temperatePinguicula]
- International Carnivorous Plant Society, Growing Mexican Pinguicula [carnivorousplants.org/grow/guides/MexicanPinguicula]
- Sarracenia Northwest, Venus flytrap care [growcarnivorousplants.com/venus-flytrap-care]
- Sarracenia Northwest, Sarracenia care [growcarnivorousplants.com/sarracenia-care]
- Sarracenia Northwest, How to grow Cephalotus [growcarnivorousplants.com/cephalotus-follicularis-care]
- California Carnivores, Australian pitcher plants (Cephalotus follicularis) growing tips [californiacarnivores.com/blogs/growing-tips]
This tool is editorially reviewed and its advice is checked against the cited sources. Last reviewed: October 2026.