Do Tulips Close Up At Night? (Why+Possible Problems Of Not Closing)

Tulips are attractive flowers famous for their beauty and colors, but also their behavior and style. These plants tend to modify themselves according to the environmental conditions around them. If you have tulips in your garden, you will find them closing up during the night.

But why do they do so? Why do tulips close up at night? Let’s find out.

Tulips close up at night to protect their pollen from moisture and insects. This closing-up process during a rainy day or at night is called nyctinasty. It helps the pollen of tulips stay protected for the following day when they are ready to attach to pollinators for the reproduction cycle.

Besides, the tulip petals will remain closed in cloudy conditions as well. Tulips blooming during the day and closing during the night is a sign of a healthy tulip.

If you want to understand the opening and closing movements in the tulips, read this guide to understand and know the various reasons behind such movements and how the tulips benefit from these movements.

Tulip indoor

The usual phenomenon in the flowers

The two usual phenomena found in some kinds of flowers are:

  • Opening up in the daylight
  • Closing up in darkness

Many flowers tend to open and close according to different factors like heat, temperature, humidity, light, etc.

The petals tend to open up in broad daylight, and when dusk arrives and the temperature drops, the petals close themselves.

Tulips, too, react the same, relying upon the light and temperature variations. This behavior is also called nyctinasty.

Other types of flowers having the same behavior

There are many flowers available which will open and close. In this guide, we will be talking about tulips.

But other than that, flowering plants with this same behavior are daisies, snapdragons, roses, geraniums, etc.

Tulips are beautiful flowers available in various bright and vibrant colors. Tulips possess a deep purple tulip variety known as the Queen of the Night.

The interesting fact in this variety is that it appears black in some lights and purple in ordinary. They are getting famous day by day.

However, there is no sunlight left for the tulips to receive enough solar energy. So, they will remain close.

The reasons for which the tulips remain closed during the nights

The tulips remain closed at night because:

  • They are taking a rest
  • They are protecting their pollens from insects
  • They close to reduce moisture loss

Why do Tulips sleep?

Plants use different resources to get their best-growing conditions for themselves. Thus, they need to adapt to every environment to improve their growth, development, and reproduction. 

Similarly, tulips will also adjust themselves to their surrounding temperature depending on the day and night cycles.

Tulips will close their petals during the night and open in the morning. It is something you shouldn’t worry about as it is their natural way of resting at night.

Tulips opening and closing depend primarily upon the light and temperature they receive. This nature is called nyctinasty. It is a 24-hour rhythm.

Humans have a nervous system that works as a regulator for their sleeping and waking. But plants do not have such a thing.

But they have circadian rhythms like humans. The chemical signals inside the plant allow the system to run on its own.

Moreover, when the night appears, the plants don’t get any energy from the sun for photosynthesis. As there is no photosynthesis, tulips will thus take some rest and sleep.

Why do tulips need to protect their pollen and nectar?

Tulip in sun

During the day, the tulip petals remain open for pollinating with the help of bees and butterflies. But they don’t roam about during the night, but some notorious pests do.

When the tulips close up during the night, they protect their pollen and nectar, and other reproductive parts from these pests. Moreover, the insects that transfer the pollen roam about during the day.

So, there is no reason left for the tulips to remain open other than protecting them.

Another reason tulips close is to protect these pollens from getting wet by dewdrops. 

Wet pollen and nectar reduce the chances of any further reproduction and multiplication. Wet pollens will become heavy, and the pollinating insects will not be able to carry them.

Dry pollens will be easy to carry and distribute, resulting in reproduction.

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Tulips closing to reduce moisture loss

Usually, plants transpire the whole day. During the night, guttation occurs to release the excess water from the plants. But sometimes, too much water loss occurs. 

So, tulips closing up during the night can also happen because they reduce excess moisture loss from the plants.

Moreover, if guttation occurs, the water can drop down and reach the soil, taking little care of the watering.

Which part of the tulips close at night?

Tulips close their petals at night, and the following day they will again open widely.

How do the tulips close and open?

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The tulips tend to open and close their petals due to cell expansion.

When the sun warms up the tulip petals in the morning, the liquid pressure inside the cells at the petals’ base will increase. This pressure is called turgor pressure. 

When the cells expand due to pressure, they become rigid and result in the unfolding of the tulips. But at night, no sun will warm up the petals or create or increase any turgor pressure. 

As no warm-up or turgor pressure occurs, the cells don’t expand, and thus they close up at night. Another reason behind tulips closing at night is the chemical auxin. 

When the sunlight touches the tulip petals, it hits a chemical that makes the cells grow and expand. 

But, when the sun sets in and darkness arrives, no light is left to trigger this chemical, and no expansion occurs. Thus, the petals will close up during the night.

But, if your tulips receive light even after sunset, for example, any artificial light, the petals won’t close. Whatever light it is, it will make the tulips open wide.

Can tulips be called Heliotropic and Photonastic plants?

Before discussing, I would like to tell what these two terms are.

The first term, Heliotropic, refers to those plants that react in movements according to the sun’s path all day.

By following the direction of sun movement, the plants tend to move and absorb all the energy they need for photosynthesis’s good performance. 

Speaking of tulips, you can call them Heliotropic plants because their movement sometimes depends on the sun’s direction.

Tulips are always trying to be in the best position to get an ample amount of sunlight. They will be twisting, arcing, or moving all day to get the most of sunlight.

The second term, Photonastic, refers to those plants opening and closing in reaction to the change in light conditions.

These movements will occur if plants are getting artificial lights during the night. This is slightly different from nyctinasty.

Tulips do have nyctinasty behavior as they close during the night. But they are also called photonastic plants.

Tulips tend to close according to the light movements. Thus, when they do not get light, the tulip petals will close.

Benefits of Heliotropic and Photonastic movements

Heliotropic movement benefits the tulips in receiving the maximum amount of warmth and energy from the sun. The more energy they get, the better they will photosynthesize.

A good amount of light will create a welcoming environment in your tulips where the insects can arrive more and help in pollination.

The Photonastic movement in the tulips will help to conserve and store all the warmth and solar energy received from the sun throughout the day. 

This energy will be wasted if flowers remain open. So if your region receives gloomy or cloudy weather the next day, they can use this stored energy for themselves.

What happens if the tulips are not closing at night?

Tulip drooping

Sometimes, you might see that the tulips are not closing at night. Closing is their normal behavior, but not closing means something is wrong.

While growing tulips, you should know certain things to see them close up daily. Below I have mentioned some points in brief:

Watering during the night

You should avoid watering during the evening or at night. Tulips will close their leaf pores at night, so there will be no transpiration or evaporation. 

Moreover, photosynthesis stops due to a lack of sunlight. This means your plant won’t lose water. So, the plant cells remain turgid, and no water is required.

In such conditions, watering the tulips at night is not a good idea. The plant will not accept any water or will intake very little water. The rest unused water will remain in the soil and make the soil damp and soggy.

This will suffocate the roots, making it difficult for the plant to receive oxygen. Naturally, without proper oxygen, the tulips won’t sleep at night and will remain open.

This will also cause root rot, and many other problems will arise, like fungal infections and diseases. So, the rule is not to water tulips at night.

Excessive light

As I explained earlier, tulips are photonastic plants, and they will not close until the lights around them are off. 

If they don’t have any artificial lights around them, they will have nyctinasty behavior; they will close at night and open in the morning. But if your tulips have artificial lights around them, they will not close up.

So, if you want the tulips to remain closed during the night, make sure they are not exposed to any artificial lights at night. 

Moreover, the closing of tulips is vital for them to protect their pollens and reduce excess moisture loss.

Reasons behind tulips opening in the morning

As this article concentrates more on tulips closing up at night, I have discussed all information about it.

But along with that, I would like to add the opening of tulips in the morning briefing. Knowing about both sides of the coin will help you understand the reasons behind the opening and closure in tulips.

The two main reasons for which tulips open up in the morning are:

  • For photosynthesis
  • For pollination

Why do tulips open for photosynthesis?

Tulips opening during the day is the plant’s response to light and temperature. When the sun rises, tulips become active and start absorbing energy from the sunlight for photosynthesis. 

As they absorb energy for photosynthesis, the petals start opening, making the plant survive.

For pollination

The insects and birds that help pollinate flowering plants don’t remain active during the night. Tulip petals opening in the morning signify that they are active and ready to pollinate and reproduce.

Reasons behind tulips not blooming in the morning

Tulip 2

Tulip petals opening in the morning is a natural and daily process. When you see that tulips are not opening, it signifies that there is some environmental problem.


If your tulips are not blooming, the reason can be soil. Tulips will not tolerate excess water in their soil bed. This can make the tulip bulbs rot. 

Choose an ideal planting site where the soil is well-drained. Avoid areas having clayey soil. Add a layer of mulch to your tulip bed for excess moisture absorption.

Also read: What Kind Of Soil Is Good For Tulips? (Best Soil Mix)


As the opening of the tulip petals depends on the light and temperature, low light conditions will not allow the tulip petals to open up in the day.

It can happen if the weather is gloomy or cloudy and proper sunlight has not yet reached your tulip bed.

Another reason is location. Choose a planting site having no tall trees or buildings around, and sunlight can adequately reach your tulip bed.

Tall trees and buildings can block the sunlight from reaching your tulip bed. You might need to transplant your tulips in such a situation.

Also read: How Much Sunlight Do Tulips Need? (Tulip Light Needs)


Tulips will not enjoy waterlogged conditions as that will trigger root rot. If your plant is not healthy, it will not open in the morning. 

Avoid overwatering your tulips, especially when they are dormant. If your region has recently received rain, avoid watering for some days until the soil dries up a bit.

Also read: How Often Do Tulips Need To Be Watered? (Tulip Watering Needs )

Final words

Tulips are widespread flowers as they are found in various colors. Opening and closing up of the tulip petals are the two everyday situations in them.

When these two happening occurs, it signifies that your plant is healthy. These two movements in the tulips are primarily due to the expansion of the cells.

The tulips close because they need to protect their pollens, and they sleep at night. If they don’t close at night, there must be some problems like overwatering or too much light.

Try to solve it immediately so that your tulips can rest at night and protect their pollens and other reproductive parts from night robbers.

Source: WikipediaNorth Dakota Stae UniversityThe Royal Horticultural Society.


Hello everyone, My name is Richa and I am here to make you a better gardener by creating an in-depth and helpful resource for all the fellow gardeners out there. If I could help even a few people understand their plants better then I call it a success for my efforts.

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