Why Are My Tulips Opening Up So Much? (Possible Causes)

Besides being available in a wide range of colors, tulips are also recognized for their two phenomena. Tulips tend to open up in the morning and close up in the night, a behavior called nyctinasty. But, when tulips remain wide open even during the night, it is bizarre and indicates some problem.

In this article, we shall learn all about why are my tulips opening up so much and how you can fix the same.

Generally, tulips tend to open during the day and close by night. However, if your tulips are wide open even during the night, then the two possible causes include watering during the evening or excessive heat and light. Look out for possible problems and take the necessary steps to fix them.

If you find your tulips are opening up even during the night, read and follow this guide to know and understand the reasons and how you can fix the problem. We will also cover some brief information about the opening and closing of tulips to help you understand the phenomena.

Tulip misting

The 2 phenomena in the tulips

Before getting to the actual part, it is crucial to understand the question, “Why are my tulips opening up”? 

2 common phenomena are seen in the tulips:

  • Opening of the petals in the morning.
  • Closing of the petals when the sun sets in.

Not only tulips but many other flowers such as Daisies, Rose-of-Sharon, Snapdragons, Geraniums, California poppy, Morning glory, etc., open in the day and close their petals at night.

This phenomenon in the tulips occurs according to heat, sunlight, and temperature. When the light reaches the tulip petals, they remain wide open, and when the light disappears, they close their petals.

Just as the opening is crucial for them, similarly, the closing of their petals is equally essential. If the tulips keep opening up all the time, it would be a problem for them, which we will discuss later in the article.

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

Why do tulips open in the morning?

Before knowing why tulips keep opening up all the time, let’s learn why they open their petals in the morning.

Tulips tend to bloom open in the morning because they come in touch with the sunlight. The tulips react according to the heat and light. So, when they get light, they open themselves up. 

Moreover, when the tulips open wide in the morning, it is an indication that they are ready for 2 things:

  • For synthesizing their food
  • For pollination

For photosynthesis

Tulip in sun

As I mentioned earlier, tulips react according to light and temperature. So, during the day, sunlight provides the tulips with enough energy for a good performance of photosynthesis.

When the petals open in the morning, it indicates that the sleeping time for tulips is over, and they are active for daytime functions.

During the day, when the tulips open and become active, they immediately start absorbing all the energy from the sun for performing photosynthesis. This whole process is essential for the tulips to survive.

Not only does sunlight support photosynthesis, a good amount of light and warmth from the sun will also promote abundant blooming and maintain prominent colors in the flowers.

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For pollination

When the tulips open up themselves, it means that the tulips are ready for pollination. In the morning, the birds and insects responsible for pollination also get active.

When the tulips open up in the morning, it means that their pollen is ready for pollinating and sticking in the bodies of the hungry insects. Once the insects arrive in the tulips, the pollens get attached to their body. 

The insects carry these pollens and transfer them to other tulips (male to female) for reproduction.

Why do tulips need to close up in the night?

Just as a tulip opening up in the morning is essential, closing up their petals at night is also essential. They need to close during the night because:

  • They protect their pollen and reproductive parts from night robbers or getting wet due to dew.
  • The insects won’t be able to carry heavy pollens for pollination. Moreover, the pollinating insects remain active during the day. So they don’t have any reason to remain open.
  • They are resting and sleeping. Tulips have circadian rhythms like humans, which work as a regulator of sleep and waking up. 
  • They reduce moisture loss. Tulips can lose excess moisture through guttation. By closing up, the plant will reduce losing moisture.
  • All the energy and warmth tulips receive from the plant will be conserved in the flower once they close their petals. These can be used for the next day blooming. 
  • This conserved energy will get wasted if the flower keeps opening up. It will also be helpful if the next day gets gloomy and rarely sunlight is available. Tulips can use that conserved energy for themselves.

Why are my tulips opening up?

Tulip indoor

Now comes the primary part, where we will discuss why tulips constantly open up, even during the night.

Now, the tulips opening up in the night is something to worry about. This is because by remaining open, they won’t be able to protect their pollen and reproductive parts, and as a result, the plant will fail to pollinate and reproduce more tulip flowers. 

Now, let’s learn why the tulips keep opening up:

Watering the tulips at night

The first thing you should remember while watering tulips is they don’t require much water, unlike other plants. 

Tulips need to be watered with only 1-inch of water once per week. This will be good enough to keep the tulip bed evenly moist. 

Tulips will also not enjoy remaining in drought conditions for a long time. 

But, it would help if you do not water the tulip bed at night. This results in overwatered tulips. Tulips close their stomata after the sun sets and dusk arrives.

As the tulips close their leaf pores, the plant will neither transpire nor evaporate nor will they photosynthesize without sunlight. So, tulips will not be losing this excess water.

As a result, the water you give them will be absorbed very little or won’t be absorbed at all. This unused excess water will remain in the soil, thus making the soil bed waterlogged.

This excess water will suffocate the roots, and the plant won’t receive enough oxygen. Due to the lack of oxygen, the plant will not relax and will remain open up.

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

Excessive light

Tulips are referred to as photonastic plants. They move their petals, close and open them according to light movements. So, as long as there is light around them, they will be opening up.

As I discussed previously, tulips open up when they receive the morning light.

Now, if tulips keep receiving light even after sunset, the tulips will keep opening up and won’t close. This happens when they are receiving excessive light from the outside.

During the night, there is no way of getting sunlight. So, if there are any artificial lights around the tulips, they will remain open. 

You have to make sure that they get protection from these artificial lights. Only then can you see the tulips closing up. They won’t remain open.

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

Too much heat

Tulip drooping

Along with sunlight, comes warmth and tulips will be receiving and soaking that warmth. As with light, the tulips will get this heat too, and they will not close if the temperature around them doesn’t cool down after sunset.

Tulips are photonastic plants because they react according to heat and light. This is why tulips are constantly receiving heat when exposed to excess light during the night, i.e., artificial lights. 

When the tulips keep receiving the heat at night, their petals will remain opening up during the night too.

This behavior is quite different from nyctinasty because, in nyctinasty, the closing of tulips depends on an internal 24-hour rhythm.

Another way from where they can receive excess heat is from the afternoon sun. As tulips love sunlight, there is no question to creating any filters to block the sunlight.

But if the tulips grow in zones 4 through 10, they receive too harsh sunlight, especially the afternoon sun. While exposed to harsh sun, they will get heated up and take a lot of time to cool down even after sunset. 

In such conditions, they can remain open for a long time, even after sunset.

Also read: What Temperature Do Tulips Need? (+Growing Them At Different Temperature)

How can you keep the tulips from opening too much?

When you find that the tulips are opening too wide, even during the night, then you need to fix them. Try altering the ways of giving them their requirements.

  • Avoid watering the tulips during the night. If you have not watered the tulips for a long time and show you underwatering signs, wait for the following day. Water your plants in the early morning between 5:00 am, and 9:00 am. The plant will then get the whole to dry up.
  • Check if they are receiving too much light. If you find they are not closing and there are some artificial lights fixed, protect them from such lights. You can create a shade as an obstacle to block the light.
  • Sometimes, the sunlight intensity, especially the afternoon sun, becomes too harsh for the tulips to handle. This excess heat can make the tulips remain open for a long time, even during the night. You can create a temporary filter for them to save them from harsh sunlight.

What is Heliotropism and Photonastism?

Here, I would like to share more about Heliotropism and Photonastism.

In heliotropism, the plants keep track of the sun’s movements. In whatever directions the sun moves, the plant will turn to receive an ample amount of sunlight. They get energy from the sun to perform good photosynthesis.

In photonastic movements, the plants keep track of light movements, be it sunlight or artificial light. The tulips will remain open until there is darkness around them.

Generally, tulips move by following the sun’s path by twisting or arcing. Along with that, tulips will remain open until the light gets off around them.

Tulips benefit from both these behaviors. In heliotropism, tulips tend to gather as much energy and warmth they need from the sun, which will attract insects for pollination

In photonastic movement, the plant will close when there is no light; this closing helps conserve all the light and energy they got from the sun to use for the next day blooming. 

Final words

A tulip opening up is not the problem. In the morning, their opening is standard, but at night, their opening is something you should not overlook.

The tulips need to remain closed during the night for resting, protecting pollens, reducing excess water loss, and conserving the energy from the sun to utilize it the next day. 

So, when they are opening up, they won’t be able to do any of the mentioned tasks, which is not ideal for the tulips.

Thus, you should take care of them and try alternate methods to keep them from opening up too much. Avoid overwatering and don’t expose them to excess light and heat to keep them from opening all the time, especially at night.

You can try a small trick to keep them from opening, i.e., you can water them with cold water. It might help in closing the petals. Besides, it might also help to perk up the stems. But, don’t continue this.

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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