FlytrapCare Carnivorous Plant Forums

Hey all,

I've been growing VFTs a few years and I've never been quite sure about freezing temperatures when it comes to VFTs/Sarracenia. Normally whenever it drops down to freezing temps I just move my plants into the garage to protect them, since I'd rather be safe than sorry.

However, recently when discussing dormancy online, I've had someone insist that I'm doing it wrong, and that VFTs need to encounter frost in order to produce "antifreeze" cells that will protect them from freezing temps, and that I can just leave them outside to freeze into a solid block of ice and they'll still be fine. They linked me some Sarracenia Northwest videos where the same is discussed.

Is any of this true at all? Because even in the same video that got linked to me, I saw people in the comments section saying they left their plants outside during frosts and they all died. I've also definitely seen people keep their plants outside during freezes lose them, and I'm pretty sure having the media freeze and thaw repeatedly is bad for the plants anyways.

I know that bigger pots/bogs tend to do better with freezing temps, but they insisted that their 4" pot VFT survives freezing temps with no problem as well.

I've seen Sarracenia Northwest's videos from December and January: an inch-thick sheet of ice spanning the entire 1020 tray, pots frozen in place, half an inch of ice over the flytraps. The plants must be able to survive this, or the nursery would give them more cold protection.

Having said that, I don't want to risk my plants under those conditions. I've spent too much time, effort, and money on them, and I would be sick if I lost most of them because I neglected to give them some protection from excessive cold. If someone else wants to test the minimum survivable temperature of their flytraps, I wish them luck.

My plants have never had any issues with "some" cold. If the nighttime low doesn't drop below 25°F / -4°C, I don't worry about them. My trays have little or no standing water during the winter. Sure, the moss layer on the top of the pots freezes rock-hard, but my flytraps aren't fazed by it. If the temperature is going to drop lower than this, and the daytime high will struggle to hit the freezing mark, then I'll put up my portable cold frame, stick the greenhouse heater in it, and set the thermostat at 40°F / 4°C.

Cold weather does cause the plants to produce more anthocyanin (the red pigment), which gives them more protection from the cold. This may be where that that "antifreeze cells" idea came from.

The biggest issue that I have during the winter is cold, dry, north winds. This has a freeze-dry effect and will suck the water right out of my pots. Nothing appears to be wrong, and then I pick up the pot and discover that it's light as a feather.

MikeB wrote:I've seen Sarracenia Northwest's videos from December and January: an inch-thick sheet of ice spanning the entire 1020 tray, pots frozen in place, half an inch of ice over the flytraps. The plants must be able to survive this, or the nursery would give them more cold protection.

Having said that, I don't want to risk my plants under those conditions. I've spent too much time, effort, and money on them, and I would be sick if I lost most of them because I neglected to give them some protection from excessive cold. If someone else wants to test the minimum survivable temperature of their flytraps, I wish them luck.

My plants have never had any issues with "some" cold. If the nighttime low doesn't drop below 25°F / -4°C, I don't worry about them. My trays have little or no standing water during the winter. Sure, the moss layer on the top of the pots freezes rock-hard, but my flytraps aren't fazed by it. If the temperature is going to drop lower than this, and the daytime high will struggle to hit the freezing mark, then I'll put up my portable cold frame, stick the greenhouse heater in it, and set the thermostat at 40°F / 4°C.

Cold weather does cause the plants to produce more anthocyanin (the red pigment), which gives them more protection from the cold. This may be where that that "antifreeze cells" idea came from.

The biggest issue that I have during the winter is cold, dry, north winds. This has a freeze-dry effect and will suck the water right out of my pots. Nothing appears to be wrong, and then I pick up the pot and discover that it's light as a feather.

Yeah, that's my opinion on the matter as well. I've only been in the hobby for like 3 years, but I would be horrified if I lost any of my plants to freeze just because I didn't take them into the garage, which takes like five minutes.

I was just super frustrated because this person always enters every Reddit thread about dormancy and says it's a huge "misconception" that VFTs can't handle freezes, and how they always leave their plants outside and they freeze into bricks and everything is ok, but personally I'm like, half of these people on these threads are beginners who don't know what they're doing, I'm not really comfortable with telling people who just bought VFTs to just leave them outside all winter and then leave the hobby when they freeze to death, just because "in theory" they should be able to survive.

People keep saying that flytraps live in an environment that freezes. This is true. It is also true that those plants do not grow in pots, are not sitting on a wooden deck, and are not left unexposed to the weather. They grow in soil that is deep with a natural water level. The grow in sphagnum moss and grasses that protect them from the wind. And some of those flytraps die. Others do not. Losing 1% of a local population of thousands of plants because they didn't handle a freeze is not the equivalent of losing a $50 cultivar because you didn't protect it. The flytraps we grow are not in their natural environment, despite our every effort to mimic it. We need to adjust our care for them accordingly.

I get a similar argument from horse people about putting a blanket on my horse. They say, "The wild horses in Montana don't get blankets." That's very true. They also don't live to be 30 years old. If a blanket will make my old horse comfortable during the winter, then that is what needs to be done.

Error on the side of caution, and you will never regret not doing it.

OK, Here in the PNW we have been hitting just at freezing at night and low 40's during the day for the past week or so. It is expected to be this way for the next couple days and then back to our normal rain. I have about 8 or so of my Sarrs still needing to be brought inside to put in garage. Do you think the plants that have been left outside will be alright in light of this? I did water them once last week as it had been several days without rain. They still seem damp to the touch.

andynorth wrote: ↑Tue Nov 28, 2023 4:03 am I have about 8 or so of my Sarrs still needing to be brought inside to put in garage. Do you think the plants that have been left outside will be alright in light of this? I did water them once last week as it had been several days without rain. They still seem damp to the touch.

I think your Sarracenia will be okay. Cool/cold and damp are optimal dormancy conditions. I've had to do very little watering after the cool weather set in; evaporation has dropped off sharply, and the little rain that we've gotten is sufficient to keep them damp.

Nikson wrote: ↑Mon Nov 27, 2023 7:21 pm I was just super frustrated because this person always enters every Reddit thread about dormancy and says it's a huge "misconception" that VFTs can't handle freezes, and how they always leave their plants outside and they freeze into bricks and everything is ok,

Yeah, I know who you're talking about. I've had "differences of opinion" with that Redditor before. If he/she wants to encase their plants in blocks of ice, go for it. I'm not going to recommend that to anyone else.

I live just 40 miles / 65 kilometers west of the Venus flytrap's native range, so I know what their winter conditions are like. We almost never get weather like that around here. Ice storms are uncommon, and when they do happen, the ice is usually gone within 24 hours. Ditto for snow.

Nikson wrote: but personally I'm like, half of these people on these threads are beginners who don't know what they're doing, I'm not really comfortable with telling people who just bought VFTs to just leave them outside all winter and then leave the hobby when they freeze to death, just because "in theory" they should be able to survive.

Exactly.

MikeB wrote: ↑Tue Nov 28, 2023 4:39 am

andynorth wrote: ↑Tue Nov 28, 2023 4:03 am

I think your Sarracenia will be okay. Cool/cold and damp are optimal dormancy conditions. I've had to do very little watering after the cool weather set in; evaporation has dropped off sharply, and the little rain that we've gotten is sufficient to keep them damp.

Thank you very much.

The way i see it is cold does not harm NA CP's at all, Its a side effect of prolonged deep cold that causes tissue damage. Think of freezer burn a dehydration of tissues is what makes the damage. A night in the 20's will not do much if the temp rises in the day time, but a week in the 20's will cause deep tissue damage.

Last year I had a cold snap with nights at 12f and days at 30f for like three days i covered my plants with tarps to stop air movement to slow tissue damage. My VFT's and sarr's had no damage at all even on tables, but my southern sundew's did they were much smaller come spring from losing the outer layers.