Carnivorous Plants/Dormancy protection outdoor
Hi Jeff, Jacob,
me again :-)
I have a question, although I have your DVD 1 about growing North American carnivorous plants...
You mentioned that, if weather conditions are freezing for several days, plants should be protected with a fleece mat or other cover, and also covered with mulch...so far so good... But what about plants kept in pots like from 8 cm wide pots, to 30 cm pots? Just wrap the fleece material around the pot and thatīs it? Leave the top open or cover it with mulch though?
Some people take an ordinary plastic bag, put the CP pot in, and then fill the bag with mulch. Is it a solution? If temps are above freezing for a few days again, should I remove it immediately?
And the thing about cutting off old Sarracenia pitchers before dormancy to prevent rot... Can I leave good green pitchers on it, or should I go straight and cut them all off? I read that by cutting all pitchers off, the plant wonīt loose so much water from the leaves when it is sunny in winter, on the other hand I read that green leaves might still do photosynthesis?
Sorry to bother you again with this question, but in the DVD I had a kind of feeling it concerned more garden bogs, which are certainly more easy to protect since everything is dig in the ground and therefore the roots more likely to be protected from cold winds (which is not the case for ordinary pots which are blown by these from many sides). Also, here in Cologne, we have sunny winters, but cold winds and no snow, which makes it more important to protect everything from these cold conditions.
Have a good day and thank you very much for all your precious help!
You want plants covered during cold, dry conditions. When conditions are freezing, my experience has been that cold alone doesn't kill plants, dehydration does. This is why removal of the leaves is important. You're cutting off transpiration from the rhizome. Now some species such as some S. purpurea and S. psittacina have more evergreen leaves and smaller rhizomes, so those you should let leaves remain, but they do need to be covered. Wrapping the pots is fine, but you want to make sure plants are on the ground, not up on table or benches. Being next to the ground provides extra heat, and less exposure to drying out.
You have to make some judgement calls based on how you know your weather, and what you've seen regular garden plants experience in your area. If your freezing periods tend to be weeks at a time, then you may need to leave them covered. If freezing periods tend to be short, then leaving them exposed more would be preferable. If you do need to leave them covered longer be sure to spray with a fungicide.
In general Sarracenia are pretty tough as are most temperate sundews. Venus flytraps are a bit tender depending on conditions, but definitely don't want to be kept warm all winter. (Keeping them in a warm house all winter is one of the most common rookie mistakes that ends up killing them.) Here's a short list of more tender plants:
Venus Flytraps; varies a bit by particular cultivar. Typical wild-type tend to be hardiest.
Drosera tracyi and Drosera filiformis "Florida Giant"
Temperate D. binata types
Sarracenia minor, especially Florida clones
Some S. leucophylla types; varies; "Titan" has been tender for us.
Hybrids vary in hardiness. It tends to be plant by plant depending on the parent plants. I've found very few tender hybrids.