You might think plants are still and silent—but look closely, and you’ll discover they’re constantly in motion. One of the most fascinating examples of this is nyctinasty, a natural phenomenon where certain plants move their leaves in response to light and darkness.

If you’ve ever seen your Calathea close its leaves at night or a prayer plant (Maranta) fold upward like hands in prayer, you’ve already witnessed nyctinasty in action.

What is nyctinasty?

Nyctinasty refers to the sleep movements of plants—specifically, the rhythmic opening and closing of leaves or flowers in response to the day-night cycle.

🌙 At night, leaves may fold, curl, or close.

☀️ By morning, they reopen, ready to photosynthesize.

Unlike movements caused by light direction (phototropism), nyctinasty is governed by the plant’s internal biological clock and is triggered by changes in light, temperature, and humidity.

Why do plants do this?

While we can’t ask plants directly, scientists believe nyctinasty serves several evolutionary functions:

🔸 Moisture conservation – Closing leaves at night helps reduce water loss

🔸 Protection from cold – Curling up reduces exposure to cool nighttime temperatures

🔸 Light optimization – By opening wide in daylight, plants maximise light exposure for photosynthesis

Which plants exhibit nyctinasty?

Some of the most popular nyctinastic plants include:

Calathea – Folds its patterned leaves vertically at night

Maranta (prayer plant) – Famous for its “praying hands” posture

Oxalis (false shamrock) – Closes leaves and flowers in the evening

Albizia julibrissin (silk tree) – Folds leaflets together after sunset

Legumes (like beans and peas) – Many fold their leaves or droop slightly at night

You can easily witness nyctinasty in your home. Take a picture in the evening and compare it the next morning. It’s a subtle, beautiful way to see that your plant is alive and responsive.

How does it work?

The movement happens thanks to specialized cells located at the base of the leaf or leaflet in a structure called the pulvinus. These cells change their turgor pressure (water content), causing the leaf to bend or fold.

It’s a bit like a hydraulic system:

💧 More water = leaf opens

💧 Less water = leaf closes

This movement follows a circadian rhythm, meaning it’s tied to an internal clock, not just external light. That’s why some plants will still move their leaves even in darkness for several days!

What nyctinasty teaches us as plant caregivers

✨ Plants aren’t passive—they’re actively responding to their environment

✨ Observing their movements helps you develop a deeper connection

✨ You can better notice signs of stress if you regularly watch how they behave

At Planteka, we believe that understanding your plants’ natural rhythms is key to caring for them better. When you notice your Calathea hasn’t moved overnight, it may be telling you it’s too cold, too dry, or not getting enough light.

FAQs about nyctinasty

Is it a sign something’s wrong?

No! If your plant folds at night and reopens in the day, that’s healthy nyctinasty. However, if the movement stops or looks abnormal, it might be stressed.

Do all plants move like this?

No—only certain species exhibit nyctinasty. Others may show different types of movement, like phototropism (leaning toward light) or thigmonasty (reaction to touch, like in Mimosa pudica).

Can I influence nyctinasty?

Yes—keep a consistent light schedule, and provide stable humidity and warmth. This supports your plant’s natural rhythm.

Curious to learn more?

If you’re fascinated by how your plants behave and want to deepen your knowledge, our Plant Doctor team can help you understand what your plant is “saying.” You can also explore our course for beginner and intermediate plant lovers.

💬 Have you noticed nyctinasty in your plants? Which one puts on the best nightly show? Tell us in the comments!