Q/A #10 - Can Drosera capensis Handle an Overnight Frost?

QUESTION:
I recently ordered a Red Leaf Drosera Capensis Sundew from you, which arrived a few days ago. It was in very healthy condition upon arrival and bearing trace amounts of nectar already. I live in Lynchburg, VA, and the past couple of weeks have been particularly cold, dropping below freezing most nights. I have a collection of carnivorous plants that I keep inside a non-heated greenhouse on our apartment's south-facing porch during the winter. (It's my first winter with carnivorous plants.)  The plants are falling into dormancy with the cold temperatures and appear to be doing well in that regard. 

Since I have another cape sundew (green) sharing space in the greenhouse (and that has dealt with the cold just fine so far), I placed the red leaf sundew in with the others. Unfortunately, these past couple of nights have been particularly chilly, and I woke up this morning to find the temp inside the greenhouse had dropped to 25F overnight. Upon inspection, water tray was frozen, along with the soil of all the carnivorous plants! Yikes. My other plants (Sarracenia, Venus Flytrap, and the aforementioned green leaf sundew) appear to have weathered it just fine due to dormancy. 

However, the red leaf Drosera I just received has completely drooped all the way down to its pot. Some of the stalks are browning, but there is still some red to be found (especially on the crown). I am keeping all plants (including the red leaf sundew) inside our apartment in front of a south-facing window for now. Everything has thawed, but the red Drosera still looks sad. I did some research, and it sounds like Drosera Capensis is quite robust and capable of bouncing back from bad conditions come springtime. I even read they can die back to the roots and sprout again when things warm up. 

My question is: should I keep the red leaf sundew inside our heated apartment until warmer spring weather comes? And do you think it will recover from this incident? 

I will likely move the other carnivorous plants back into the greenhouse when the weather warms up a bit next week. I don't want to accidentally awaken them from dormancy with our apartment heat! But temps below freezing are certainly too cold for them, I think. The Drosera Capensis Red Leaf Sundew is still within its provided soil and pot. I use store-bought distilled water in a tray. The plants receive several hours of direct sunlight each day (that's the best I can do in the winter) and a lot of indirect sunlight. Thank you so much for your time!
(Submitted in January 2022.)

RESPONSE BY JEFF DALLAS:
Looking at the photo, it does look like you lost all the leaves, but I can't tell for sure if the crown is still alive or not. Most likely it will bounce back from the roots since the soil probably didn't freeze solid. Moving the Cape Sundews indoors for winter is the best thing to do since it sounds like you don't heat the greenhouse. 

Cape sundews are not truly hardy. They come from South Africa, and can experience frost once in a while, but it's not common. They won't die down to a winter resting bud (hibernacula) the way temperate sundews such as Drosera rotundifolia or D. intermedia will. It's better to think of these as cool-growing tropicals. For this reason we group them with the tropical sundews in our nursery. Their greenhouse is in the 50's at night, but upper 60's during the day in winter.

With that said, we had a colony of Red Cape Sundews overwinter outdoors.  We forgot about bringing them into the tropical greenhouse until only after we had a freeze.  The plants died back to the soil, so we figured we'd just leave the pot alone and deal with it later.  In spring, the plants came back from the surviving root stock, despite the pot having froze solid at some point during the winter since we had a week of 25°F (-4°C) weather.

So it's possible to keep this plant outside in winter like you do with temperate sundews. Yes. How much of a freeze they can withstand?  We don't know. What we do know is that this plant grows best year round in a sunny windowsill. Make sure to follow the directions in the yellow brochure that came with your plant.  

With your Sarracenia and Venus Flytrap, you can keep them in the non-heated greenhouse. We keep our plants outside, and the pots freeze solid every year.  The plants also come back every spring.  There's no reason to protect them from the conditions you described.

• Submitted in January 2022. The original question and response have been edited for publication.
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