Why is My Bougainvillea Dropping Flowers? [Complete Solution]

Bougainvillea is an ornamental plant. A harmonious blend of spectacular shape & alluring flowers adds quite a view to your garden & gets you so many “wow” reactions from the viewers.

As bougainvillea flowers are the center of the show, nothing is more frightful when your bougainvillea starts dropping its blooms.

After all that care and time, It’s hard to deal with, right?

Anyway, don’t sweat it. You are not alone in this.

Lower quantity of temperature, humidity & light level, over & under watering, improper fertilization, exposure to ethylene & too dry soil can cause your bougainvillea to lose its flowers.

This article will help you understand the reasons properly & will provide you with the best solutions.

So, if you don’t want your bougainvillea flowers to drop off, stick with me.

Bougainvillea Flower Drops-Quick Fixing Guide

Reason Solution
Low Temperature Keep them in 24-30℃
Low Light Level Place them in direct sun or use artificial light
Overwatering & Underwatering Increase drainage and water only when soil is completely dry
Low Humidity Spray cool water mists
Improper Fertilization Apply Bougainvillea fertilizer according to the label direction
Exposure To Ethylene Keep away from fruiting plant
High Pot Temperature Keep the soil moist

Reasons & Solutions of Bougainvillea Flowers Dropping off

Bougainvellia long lasting blooms

Before I start analyzing every single pixel, I want to disclose the bigger picture.

Have you wondered why flower dropping occurs in the first place?

To begin with, Plants tend to drop their organs, like flowers, buds, fruits, etc in response to stress. Here is one thing you may overlook. Have you noticed that the organs I have mentioned can be grown again? Quite interesting, isn’t it?

Certainly, you might be thinking, what creates stress conditions for plants, right?

Well, let me tell you briefly. Plants get stressed almost whenever the plant doesn’t get the required sunlight, proper temperature, water, air, and nutrients.

Your bougainvillea will keep growing and maintain flowering and others as long as its requirements are being fulfilled properly.

Now let’s say, your bougainvillea is facing troubles with its requirements which result in stress. & one fine morning, you observe that your bougainvillea has started dropping off its flowers terrifically.

Now the question is why it drops its flowers when it is under stress?

Come on. Who doesn’t want to release stress?

Let me tell you what your bougainvillea is probably thinking before starting to lose its flowers. Perhaps it was thinking something like this – “Okay!! I am under stress. My requirements are not fulfilled. So what can I do?? Let me adjust to what I am getting & lower my demand. I have flowers in me. Let me drop these. They require too much. I will grow them again later. 

And the result? Flowers start to drop off.

So have we got that straight? I think that’s basic enough to understand properly.

Let’s dive into the details with solutions to your problem.

1. Low Temperature

One of the prominent reasons behind flower dropping off is low temperature.

If your bougainvillea has passed or passing cold weather, it may be facing stress due to low temperature.

Well, obviously the environment is something that you don’t control. It depends upon your geological position.

The optimum temperature for bougainvillea is 24 to 30-degree celsius. And the minimum temperature that bougainvillea can tolerate is 0 to 4 degrees celsius.

Interested to know how low temperature affects?

Low temperature can create stress in your bougainvillea in various ways.

It affects the nutrient uptake of your plant by decreasing the activity of the plant enzymes. Less supply of nutrients can induce stress.

In another way, If you weigh a plant, you will see 80-90% of its weight is due to water. And you must know how water reacts to cold weather, right?

Good thing is, Bougainvillea can tolerate a temporary low temperature, maybe for 2/3 days. But a longer period of low temperature can cause stress conditions followed by losing flowers of your bougainvillea.


Once your bougainvillea starts dropping its flowers because of low temperatures, then hardly you have anything to do.

If you are doing container gardening, then simply you can bring the pot into your house. 4 degrees celsius is a perfect time to bring your bougainvillea inside. Keep it there for some days until the temperature increases. Otherwise, if it’s possible, transplant your bougainvillea in a pot & keep it indoors.

Undoubtedly in such cases, Prevention is the best choice.

Let me tell you what preventive measures you can take-

  1. Choose a native variety of bougainvillea to grow in the first place.

You know, Native varieties are already adapted to the environmental condition of your locality. Trust me, you can avoid many worries concerning your bougainvillea simply by choosing a native variety

  1. In the case of container gardening, place your bougainvillea far away from the air Conditioner.
  2. Keep track of the weather update

If there is a possibility of heavy frost, you can cover your bougainvillea plant with polythene. But polythene should not be touched with the foliage. And try to remove it as early as possible.

2. Low Light Level

Bougainvillea is a light-loving plant. It doesn’t like shades. Direct sunlight of 6-8 hours is its prominent requirement.

Bougainvilleas can grow in a place having partial shade, but sorry to say, this won’t be sufficient for blooming in the first place.

That’s why I want you to understand one thing straight & that is you have to ensure uninterrupted light for your bougainvillea.

Low light levels cause difficulties in photosynthesis. In the plant world, there is no restaurant. Plants can’t just order some nutrients from a nutrient-serving restaurant or something!! Every day they had to cook to survive. That’s why photosynthesis is very important. And lack of it can cause stress and eventually lead to the dropping of flowers.


  1. First of all, ensure direct sunlight. If anything is interrupting the light, if possible, remove it.
  2. Help your bougainvillea in getting light.

How can you do that? There is a very simple way. You can use a smooth mirror and by proper angling, You may be able to reflect light to your plant. Isn’t it impressive?

  1. Have you ever thought about why photographers use white-colored paperboards? Yes, you are right. White color reflects the most. You can use it instead of the mirror. Though it is a temporary solution, you can give it a try, right?
  2. If there is a constant problem with the light, think about an artificial lighting system. Let me suggest you one (our pick: GE BR30 LED Grow Lights for Indoor Plants)

3. Overwatering & Underwatering

Can you be honest with me? Haven’t you ever faced this watering problem? At least once?

Most gardeners face this problem. Various questions pop up in our mind while watering, for example- when to water, how much to water, etc.

Both over & under watering affects bougainvillea adversely.

Overwatering causes flooding to the soil. As a result, oxygen-containing soil air pockets are replaced with water. Lack of oxygen can cause trouble breathing for your bougainvillea.

Though bougainvillea is a drought-tolerant plant, too little water availability creates stress to the plant because water is highly required for several important metabolic activities. Mostly in container gardening, underwatering causes stress. & To release stress, your bougainvillea may start losing flowers.


  1. Interested to avoid all the water-related problems? Then water properly. You know, Bougainvillea is a drought-tolerant plant. It doesn’t need much water. Once your bougainvillea is set, you can water it thoroughly after every 3 or 4 weeks. But don’t forget to make sure that extra water is leaching away.
  2. Keep the soil moist during flowering. While flowering, your bougainvillea needs more water than regular.
  3. During flowering, do mulching to keep the soil moist.
  4. Chlorine-containing water can be responsible for flower dropping. Try to avoid it.

4. Low Humidity

Low humidity affects plants more than dry soil. Yes, you heard me! Mostly we overlook this factor But it affects bougainvillea way more adversely.

You are probably wondering, how? Let me explain-

Because of low humidity, your bougainvillea starts losing water through microscopic pores in the leaves called stomata. When this happens, it closes the stomata to check water loss. But because of the close stomata, its internal cooling system slows down. As a result, heat builds up internally, in cells, in tissues, and creates a stress condition, which ends with losing flowers.


Bougainvillea is a high humidity lover. 50% humidity level is best for flowering. To maintain this humidity level, measures that you can take-

  1. To increase humidity, you can spray cool water mists to the foliage. To know exactly the level of humidity, use a hygrometer. Out of different brands, let me suggest one (our pick: AcuRite 00613 Digital Hygrometer)
  2. Have you heard about a humidifier? If possible, get one & stop worrying about humidity permanently. My suggestion for you (our pick: TaoTronics Humidifiers)

5. Improper Fertilization

Let me say this straight- your bougainvillea does not need too much nitrogen to grow!!

Many gardeners make the same mistake by providing too much nitrogen to their bougainvillea. But this can be fatal. Too much nitrogen causes vigorous growth of leaves but creates an untoward condition for flowering.

Moreover, the plant which receives too much nitrogen attracts pests & reduces the strength of the stem.

Overdose of fertilizer can cause root damage and increase toxicity. Acid-loving plants like bougainvillea need specific fertilization.

That’s why precise fertilization is inevitable to avoid paths leading to a stress condition.


  1. Bougainvillea organic fertilizer is highly recommended. Eggshell fertilizer & mustard cake fertilizer have been found very effective for flowering. Familiar with these two? If not, give it a try. You can always thank me later.
  2. For Plenty of healthy bougainvilleas, use a mixer of N P K fertilizer maintaining a 10-10-10 ratio. If you are confused with the number, let me tell you, it is the percentage of N P K present in your mixer. That means a 100 kg mixer of this ratio contains 10 kg of each element, the rest is filler.
  3. You probably know that Epsom salt is a very common fertilizer that every gardener owns. It is very effective for flowering. Mix 2 tablespoons of Epsom salt into 4 liters of water and spray it over the leaves to get the best result.
  4. Use superphosphate to get excellent flowering. While using, put them at the corner of the pot rather than at the base of the bougainvillea.
  5. Use coffee grounds as a fertilizer. Bougainvillea loves slightly acidic soil provided with nitrogen. Coffee grounds will make it up for it.

6. Exposure To Ethylene

You may have heard of ethylene. In the plant world, the angel of ripening is ethylene. It is a plant hormone. Whenever a flower drops from your bougainvillea, you can assume that ethylene was there.

Ethylene is a prominent hormone that causes the dropping of plant organs. Whenever flowers come in contact with gaseous ethylene from the surrounding, it causes more rapid aging. As bougainvillea is an ethylene-sensitive plant, it tends to drop its flowers in response to that. Interesting?


  1. Strictly speaking, place your bougainvillea away from fruiting plants. They tend to release plenty of gaseous ethylene while fruit ripening.

7. High Pot Temperature

If you are growing your bougainvillea in a pot, then you might pay attention to this.

Though bougainvillea loves dry hot weather for pot gardening, too much dry environment can be fatal. Let me simplify it for you-

When bougainvillea is planted in the yard of your home, it can grow its root long enough to take up water from the soil by itself.

But when it is in a pot, roots can’t grow very long. In that case, if you don’t water according to its need, first the soil will get dry then it will start conserving heat into it.

Moreover, if your pot is dark-colored, or Black, in particular, it will absorb sunlight, or I might say “heat” & will create an unbearable condition for your bougainvillea.


  1. Water your bougainvillea properly. Keep the soil moist during flowering.
  2. Use drip system of irrigation
  3. Try to use a white-colored pot. White color reflects most.
  4. You can do double potting while filling the gap between the pots with sand.
  5. Mulching with pebbles can be a good idea while flowering.


Bougainvillea precisely serves the purpose of decoration. That’s why losing its flowers is unfortunate.

In this article, I have tried explaining the reasons why your bougainvillea is dropping its flowers & also provided some practical solutions.

If you have come so far, I hope from now on you will keep checking about the temperature, humidity & sunlight. Irrigation & fertilization shouldn’t be a problem anymore.  And you will keep an eye on the pot temperature and protection from ethylene too.

Now it’s your turn. So go ahead, take care of your bougainvillea. Trust me, it will reward you!

Thanks for stopping by.

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