Expert: Christopher Littrell - 12/5/2008

Question
QUESTION: Hello, I have a couple of VFTs, cape sundews, and White top
pitcher plants. I wanted to know if I should put the VFTs,
and pitcher plant into the fridge for winter? It has been
pretty chili here going from 70s to 50s but don't know how
long it will last. Also, is it possible to leave the plants
outside my VFT and pitcher plant have seemed to have
already stopped producing traps.

ANSWER: Hello Edward,

While Florida might not get truly cold winters like most of the other Northern states it gets cool enough to keep dormant carnivorous plants outside year long. As long as the plants get chilly temperatures down below 60 degrees they will stay dormant. If temperatures warm slightly for a few hours it will not really harm them, however; try to keep them lower than 60 if possible. I tend to use an ice chest with frozen water bottles around the pots. That keeps the plants chilled even in a warm day. I even leave the top open in daytime to allow light to stream in to kill fungus. In your situation you can use the open ice chest by day and just let the nightly drop in temperatures keep the plants cold until morning.

Christopher

---------- FOLLOW-UP ----------

QUESTION: Thank you for your quick response. Right now we are getting
a bit warmer like 70 to 60 and won't get to the 50s again
till next week. could these changes harm the plant's
dormancy? Do you think it would be safer to bag them all up
and place in refrigerator to make sure they get dormancy?

Answer
Hello Edward,

Plants commonly feel such weather changes in the wild. A few days of cold, a few days of warmer weather, then a deeper winter cold for extended times. If winter does not chill the air below 60 degrees there for longer than a few days at a time this winter I would suggest using artificial means to cool the plants down to a good dormancy.

I typically use an ice chest despite the extra work tranferring frozen bottles from fridge to ice chest every 12 hours. The reasons are several. The refrigerator is the most unnatural of the two methods, providing no light at all, low humidity, and dark, dank conditions that mold slowly creeps into. The refrigerator can be used, but you will need to ensure the plants are bagged as you indicated to cut humidity loss. The bag should be only slightly open to permit air exchange slowly. You might need to periodically check the plant for mold and spray with Neem oil or sulfur based fungicides. In an ice chest the plants will be less prone to mold as you can open the chest by day to allow some ultraviolet light from sunlight in to kill mold. Open air cuts back on mold by blowing mold spores away. Opening the chest by day simulates the warming and cooling cycle that occurs in nature by day and night. Opening the chest by day also provides the plants with light cues when the length of day and warm weather returns, letting them know when to break dormancy.

The only time you will need to really worry about dormancy for your plants there would be during an unseasonably warm winter that does not drop below 60 degrees for an extended time. In that case I would just use the ice chest when it is too warm and let nature do the rest when it is cool enough outside.

Christopher