Prayer plants are among the most interesting plants one can have in their home because they bring a certain liveliness, color, and movement to what may be an otherwise drab space. But why do these prayer plants experience nyctinasty, involving the “opening” and “closing” of their leaves based on the time of day?
Prayer plants close their leaves at night, possibly due to a natural response to darkness. They may also do this to reduce the amount of moisture that gathers on them or prevent insects or pests from feeding on the leaves.
The rest of this article will explore the possible reasons prayer plants close their leaves at night. Read on to learn more.
Reasons Prayer Plants Fold Up at Night
Many plants share the same common names based on their appearance and behavior, making it confusing to tell them apart. To help fix this issue, each plant goes by a unique scientific name to help distinguish it from other plants under the same family or genus.
Prayer plants are members of the Marantaceae family native to humid and wet areas like the rainforests in South America. One typical example is the Maranta leuconeura. The plant’s leaves close at night as though in prayer, earning it the moniker ‘prayer plant’.
Many plant owners may have seen prayer plants closing their leaves at night but don’t understand why. This movement seems fascinating—or even disturbing—to some people who have never seen a prayer plant before.
Below are some possible reasons why prayer plants fold up at night:
Prayer Plants Experience Nyctinasty
Many believe that prayer plants fold up at night in a movement known as nyctinasty. The word comes from “nyct,” which means night, and “nastic,” which means the movement of certain parts of plants. This movement occurs in response to darkness.
So, you can see that the term “nyctinastic” refers to movements occurring at night. It differs from photonastic movements that occur in response to the presence of light. Nyctinastic movements happen due to the lessening of the amount of light.
You may hear some plant owners claim that their prayer plants have a routine and close and open on a schedule. Based on this anecdote, it may seem that plants have a pattern similar to humans and other animals that can help them tell what time of day it is.
Strictly speaking, if the phenomenon occurs as a response to the time of day, then prayer plants must close only at night. However, many house plant enthusiasts observe that their plants close their leaves in the absence of light, regardless of the time of day. In contrast, the leaves unfold or open when there’s enough light.
Here’s a time-lapse video of a prayer plant folding up its leaves: https://www.youtube.com/watch?v=cRToxjXhbso
The video shows a time-lapse of a prayer plant folding upwards even if the light condition in the room didn’t change the whole time. It may signify that darkness may not be the only stimulus for prayer plants to move or fold up their leaves.
In addition, a study claims that leaves of Calathea lutea—another famous member of the Marantaceae prayer plant family—move up even if there is a bright light, reducing the amount of light the leaves can receive on its surface.
Prayer plants are tropical. Most family members prefer dappled sun, while others prefer partial shade. They do not do well under direct light, which may be another reason why the leaves move and shy away from intense sunlight.
Nyctinasty may be the most plausible explanation for why prayer plants behave the way they do. However, these contradicting reports show that even if it may be partly responsible for the closing of the leaves of prayer plants, many other factors may also be at play.
While the ‘evening prayer’ movement is common to members of the Marantaceae family, there may be some genus- or species-specific and environmental factors that contributed to this rare plant behavior.
Closing Their Leaves at Night Allow Them To Reduce Leave Moisture
Members of the Marantaceae are native to the tropical areas of Asia, Africa, and South America. Being tropical plants, they can benefit from high humidity. However, they do not enjoy too much rain.
Some tropical plants have developed unique adaptations to reduce the amount of water they get on their leaves. For instance, Monstera plants have fenestrations to lessen the amount of sunlight and water stored on the leaves.
In the case of prayer plants, the closure or folding up of leaves at night may be a defense mechanism they have developed to lessen the amount of moisture buildup on their leaves.
Folding up and reducing the surface area of the leaves can help decrease the likelihood of evening dew forming on them. It happens at night because there is not enough sunlight and heat that could help remove excess moisture through evaporation.
Insects and Pests Can’t Eat the Leaves When the Leaves Are Closed
Diseases and infections are rare among Marantaceae plants. However, Calathea and Maranta genera members are likely to have issues with pests or insects, such as aphids, mealybugs, and spider mites. These pests may pose a threat to the plant by feeding on the foliage.
The closing of the leaves may be yet another defense mechanism some prayer plant genera have developed to help prevent these pests from feeding on their leaves. However, it does not justify why the closing of the leaves occurs mainly at night. Aphids are known to be active during the day, whereas spider mites are primarily active at night.
Observations made by many plant owners provide some answers as to why the leaves of prayer plants close at night.
However, some scientific studies disprove some claims, prompting experts to conduct more research to determine what stimuli trigger this kind of movement among members of the Marantaceae family.
Nonetheless, the mystery of why prayer plants close their leaves at night adds to their beauty and uniqueness.
- Wiley Online Library: The functions of foliar nyctinasty: a review and hypothesis
- Merriam-Webster: Definition of Nyctinasty
- Khan Academy: Phototropism & Photoperiodism
- Bloomscape: Prayer Plant Care
- Britannica: Marantaceae
- The Healthy Houseplant: When, Why, and How Do Prayer Plants Move and “Pray”?
- Outside In: Why Do Prayer-Plant Leaves Lower and Rise, Day and Night? Some Theories Examine
- NuPlantCare: Why Do Prayer Plants Pray?
- Science Direct: Nastic Movements
- NC State Extension: Maranta Leuconeura
- Merriam Webster: Nyctinasty
- Kevin Wong: Prayer Plant Time Lapse
- PubMed.gov: Leaf Movement in Calathea Lutea
- Flora of North America: Marantaceae
- NC State Extension: Calathea Crotalifera
- YouTube: Prayer Plant Time Lapse