What is Dormancy?
During the winter months the Venus flytrap goes into a state of dormancy where the leaves will become small or die back altogether. Don’t worry they are taking a much needed rest, they are putting more energy into their rhizome development, and they will grow larger in the next growing season as a result. Dormancy seems to be triggered more so by the amount of light they are receiving and not the temperature they are exposed to so as the days become shorter as we come into winter they will begin to slow their growth and you will notice the leaves and traps may start to die back.
During this period of dormancy it is best to remove the plants from the tray watering method and top water them when the surface of the soil becomes almost dry. Depending on where you live will dictate the frequency of watering required. Often this may just be once a week or so.
You can keep watering by the tray method if you prefer. The main thing here is to keep the water to a minimum, a couple of millimeters of water in the tray over the dormancy period will be ok, so that the pot doesn’t become waterlogged as this can cause root rot.