A question about refridgerator dormancy

[lee1dew]

Hi,

This is my first post here after lurking around for a few months. I've found this forum to be a great place to learn about various carnivorous plants, so where better to ask my question?

As I understand it, CPs go dormant to "rest" after expending resources used in growth during the season. This makes sense for a plant that is dormant outdoors, as it is still being exposed to sunlight, air, a good supply of water, etc. while not using these resources for growth.

But what happens to a plant that spends its dormancy period in the refridgerator? I would think that, since it no longer has access to the materials that it needs for growth, that these resources would not get replenished. In fact, since the recommended method of refreidgerator dormancy involves darkness, no air (zipped up bags), and little water, the plants come out in pretty much the same state as they went in.

So do these plants need to go dormant to replenish resources, or does it not serve any purpose except that they are "wired" to require a dormant period?

Derrick

 

[Alvin Meister]

Hi and welcome Derrick.

The refridgerator dormancy is an artificial way to give the plants the dormancy they are 'wired' to need. Through dormancy the plant will be using up resources stored in the rhizome to survive and not to replenish resources. Most plants can't photosynthesise below 6C, so throughout winter when the temperature is below this, the plant is using up its stored energy stores. In the wild there are still plenty of days over 6C during winter and carbohydrates can be manufactured, albeit slowly, in the leaves that still remain on the plant.

In the fridge, the energy is slowly being used up, which is fine, but if you left the plant in there for a year or so it would exhaust itself.

Incidently, you can skip the first dormancy of a young plant's life to speed up maturation. After a while, the plant will decline if not given a rest the year after though, due to its inbuilt nature.

Another example of the effect of genetics is with Sarracenia oreophila. In the wild, its habitat dries out in summer, so the plant pitchers and flowers as quickly as possible in spring. In cultivation, even if kept very wet, it will stop pitchering by mid summer.