As of this writing, Dallas winter arrived a little early. The current cold front is being compared to the big freezes of December 1983 and 1989, but thankfully we’ve neither seen the snow and ice of both of those nor the power outages of 2021. It’s brutally cold, but at least we’re not getting the thundersnow of 2011, either.
It’s about this time that beginner carnivorous plant enthusiasts have questions. LOTS of questions. Based on their experience with standard houseplants, most of which come from areas that never see this kind of cold, they’re understandably concerned about their plants surviving the freeze, much less surviving to see spring. The situation is complicated with how scraggly many carnivores can get by mid-December, and that leads to a lot of frantic Instagram DMs and phone calls asking “Is my plant dead?” They’re usually reassured when they get an answer, but it’s a rough time until then.
In the interests of preserving peace and sanity, it’s time again to discuss carnivorous plant care during a Dallas winter. Your mileage may vary outside of Texas, but the basic principles apply. If you find alternatives that work better for you, I say “congratulations” without the slightest bit of irony or sarcasm: if anything, share what you discover, because it may help someone else.
Firstly, let’s start with tropical carnivores, such as Nepenthes, Cephalotus, and Heliamphora pitcher plants. Cephalotus and Heliamphora don’t mind some cold (if anything, Heliamphora needs it), but temperatures well below freezing are just as lethal to them as they would be to a lowland Nepenthes. If they aren’t all inside by now, they’re probably doomed, but bring them inside right now anyway, because there’s always a chance a frozen plant may come back from the roots. This also applies to Mexican butterworts, Cape sundews, Brocchinia, and any other carnivore considered “tropical.” They may not revive after being left outside during a 10F/-12C night, but they’ll stand a better chance than they would if they got another night of it.
If you DID bring any of these inside, congratulations, but it’s not over yet. Most central heating systems are notorious for sucking moisture out of house air, and that nice roaring fireplace just adds to the lack of humidity. Right now, the vital concern with Nepenthes pitcher plants in particular is keeping up the high humidity they need, but be careful with how you provide it. This can be provided via ultrasonic foggers, drip irrigators, or setting up a good light in the bathroom, hanging the Nepenthes underneath it, and telling everyone in the house “THIS is where you’re taking your showers every morning.” If you’re using foggers or irrigators, just make sure that the water used in it is rainwater or distilled water, as the salts and other minerals in Dallas tap water will both cake up on the fogger’s disc and reduce its life expectancy and may leave salt residue on the plants exposed to the water.
For temperate carnivores, such as Venus flytraps, Sarracenia pitcher plants, and threadleaf pitcher plants (Drosera filliformis), they should already be in the middle of their winter dormancy, so they’re going to look a little scraggly already, if not appearing completely dead. 10F/-12C is the lower end of the temperatures they can withstand, but they’ll do well if protected from the wind, either by covering them with a row cover or even an old sheet or moving them into an unheated shelter that still allows them to get full sun. If that’s impossible, they can be brought into a garage, shed, or other unheated area during the worst of the cold, but put them back out in full sun as soon as the temperatures allow. Do not leave temperate carnivores in the garage over the winter, as they still need lots of sun during their dormancy.
A caveat to the above: especially with the purpurea and rosea species of Sarracenia, the cold is far more dangerous to the containers in which the plants reside than to the plants themselves. If keeping plants in plastic or fiberglass pots, the pots should be fine if the contents freeze solid, but that’s a great way to split, crack, or chip ceramic or glass containers. Particularly with ornate ceramic pots, bring them inside just until the deep cold passes, and be prepared to bring them inside again with each following cold front. In fact, now that the plants are dormant, now may be a great time to transfer them out of that great heirloom pot you received from a relative or found at an estate sale, put them into an inexpensive plastic pot for the winter, and then repot them in the heirloom pot next spring before they emerge from dormancy. This way, if we get another major freeze right after the beginning of the new year, which is always possible in Dallas, you won’t look out on your back porch afterwards and weep over that wonderful Chinese goldfish bowl being split down the middle.
Whether you’re repotting or moving inside, now is a great time to trim back any dead growth on your plants. With all carnivores, trim off any obviously brown and dead leaves and stems, but try to leave any green portions alone unless it’s unavoidable. With Sarracenia, this is especially important, as cleaning out dead pitchers is an excellent way to minimize potential pests from getting winter shelter and to give the still-living pitchers more available light, Just give them a good trim with scissors or clippers (trim the dead portions off still-green traps, leaving a good margin of brown so you don’t stress still-living tissue), toss the dead bits on your compost pile, and keep an eye on how well they reemerge next spring without all that ecch around them.
Oh, and one last little bit concerning seeds and seedlings. If your Sarracenia pitcher plant bloomed earlier this year, now is the time to gather any seed pods if you haven’t already. The seed pod will split in order to scatter its contents around the area, so take a plastic bag and grab the pod from underneath before cutting it free from the stem, and then keep the seeds refrigerated but not frozen (a plastic jar in the refrigerator works well) until spring. There’s always the chance of previously scattered seeds germinating last fall and producing seedlings that are now out in the cold: many may not make it, but you may be surprised.
For the most part, that’s the biggest concern in the cold, but don’t forget to be careful yourself. In this sort of cold, make sure to pick up and move pots while wearing gloves to reduce the risk of damage both to the pot or your hands. Not only will gloves reduce the risk of frostbite, but they may be the only thing between your fingers and a pot that decides to shatter from thermal stress when picked up. Obviously, the worst danger is from glass containers such as goldfish bowls, but your more expensive ceramic containers have a tendency to throw off long and extremely sharp flakes when stressed in the cold, and some are so sharp that you won’t know you’ve been cut until you notice the blood. Even worse, pots that have frozen solid may hang together until they thaw, but all they need is a little bit of stress to come apart in such a way that a tetanus shot at the ER while getting sutures is a really good idea. This happened to me while assessing the damage to my greenhouse after the 2021 Texas freeze, and I was lucky that time. I’m not depending upon luck in the future.
With all of this said, please take care of yourselves and your plants, and here’s hoping that we don’t have any further massive cold bombs in 2023. The heatwave last year was bad enough.