Besides their striking appearance, calatheas have another feature that makes them special – their leaves move during the day-night cycle. If you ever wondered why do calathea leaves move, you are not alone! This question has been asked for years, and many hypotheses and scientific studies were made to try to explain this movement.
Calatheas – Prayer Plants
Calatheas (along with Marantas and some other plants from the Arrowroots family) are also commonly called prayer plants, a name that does them justice.
The leaves of these plants tend to point up at night (they are “praying”) and drop during the day. We’re not talking minor movement here. The difference is like day and night ;). The leaves can also open and close.
This is normal behavior for these plants, so calathea leaves moving is nothing to be concerned about. The movement is more noticeable with some varieties of Calathea. If you are lucky, you might even hear the leaves move (you will hear a rustling sound) as the leaves rub against each other. It might be a little freaky at first, but it’s quite adorable.
That said, only a healthy plant that has good growing conditions will move its leaves, so make sure your Calathea care is always spot on.
Why do Calathea Leaves Move?
The moving of the leaves in this manner is called nyctinasty. The general purpose of the movement of foliage with all plants is to capture the light. During the day, calathea leaves drop and assume a more horizontal position to get more light. The green part of the leaf will be facing the source of light.
The movement of the leaves during the day is pretty straightforward. However, the reasons for the movement at night are wrapped in a shroud of mystery.
As for the movement itself, it’s in the joints! The part just under the leaf, where the leaf and stem meet, is responsible for most of the movement that makes these plants special.
But what actually makes the leaves close up at night? That is up for debate. Many plants exhibit nyctinasty, and all are puzzling. There have been many hypotheses over the years as to what causes this movement, from conserving temperature to conserving nutrients, but not one clear answer has been found yet.
You can read through one of the more recent studies to learn about different hypotheses that are still being examined and any that have been abandoned.
The functions of foliar nyctinasty: a review and hypothesis by Peter V. Minorsky
Calathea Leaves not Raising
If your plant doesn’t exhibit the leaves’ movement, something is most likely off, either with care or with the environment it is in. If it’s just one or two leaves, you shouldn’t be concerned. However, if the whole plant is “stuck,” you should find the cause.
Read: why isn’t my calathea closing at night
