Bougainvillea Losing its Leaves? (How to Save it)

Why is my bougainvillea losing its leaves

Have you ever bought a beautiful bougainvillea with visions of it displaying flowers of Mediterranean splendor only to be heartbroken at the sight of the leaves scattered on the ground around it? I realize how disheartening the site of scattered leaves can be, and it is an all-too-common scenario that people tell me about online!

Because of this, I have lots of experience identifying why bougainvillea suddenly drop their leaves and how to create the right environment to prevent the leaves from dropping, and so that green leaves can regrow when conditions are better!

In my experience, bougainvillea most often lose their leaves due to cold temperatures, lack of sunlight, transplant shock, and as a sign of stress due to overwatering. Bougainvilleas are also sensitive to cold and can lose their leaves in Winter or as a reaction to a sudden change in temperature.

I think it’s important for us to note that Bougainvilleas are evergreen in hot climates with mild Winters (they flower all year round in Mediterranean environments, as you may have seen) but lose their leaves and flowers in cooler climates so if you are in a cold climate like me then we need to protect them from freezing temperatures.

I can assure you that I have first hand experience of reviving bougainvillea even if they have lost all their leaves. It is critical that we understand why it’s losing its leaves and then implement the solutions.

In this article, I’ll share with you all the tips and techniques that I have learned in a step-by-step guide so you can save your bougainvillea…

Your Bougainvillea is Dropping Leaves Due to Temperature Change

So, remember how we discussed creating the right environment for our bougainvillea to regrow their leaves? Well, I talk to my clients (I work in a garden center). I always find it helps if they understand how their plant grows in the wild…

Bougainvilleas are native to warm climates such as Brazil and retain their leaves and display their flowers in Mediterranean climates, however, they are deciduous in cooler climates. (Cold hardy in USDA zone 9)

Bougainvillea plants lose their leaves in response to cooler temperatures and sudden contrasts in temperatures, and due to lower sunlight intensity in the Winter months.

I find the sudden fluctuation in temperature is what catches people out. We need to remember that the temperature does not necessarily have to drop below freezing for bougainvilleas to suddenly drop their leaves but it can be as a consequence of an unexpected cold snap that was in contrast to consistent warm or mild weather.

So think back, or perhaps look at your weather forecast for the past few days if your bougainvillea leaves have suddenly fallen off. Did the temperature dip low unexpectedly at night? If so, this is the probable cause of the leaves dropping.

How to Save Your Bougainvillea Losing Leaves Due to Cold Temperatures

So, if a sudden cold snap is responsible for the leaves dropping, how do we save it?

If you grow bougainvilleas outdoors in cold climates as I do, then it is best practice to grow them in a pot or container so that you can bring the bougainvillea indoors before the temperature goes below 5° C (41° F) as bougainvilleas are not cold hardy and often die back in a frost.

I always keep a close eye on the night temperature on the weather app on my phone in the early spring (so I don’t get caught out by late spring cold snaps) and not Fall when the temperatures cool.

I have personally seen it when the shock of cold temperatures causes the leaves to drop but this does not necessarily mean that your bougainvillea is dying, as long as it is protected from freezing temperatures with horticultural fleece or by being indoors.

Horticultural fleece is useful if you have planted bougainvillea in garden boarders and therefore can’t bring it indoors, but in my experience, it is not a fool proof method of saving the bougainvillea from cold, so I like to grow mine in pots.

If the leaf drop has correlated with cooler Winter temperatures then your bougainvillea can recover in the Spring when the temperatures warm up as long as you place the bougainvillea in a Sunny window and water it infrequently over Winter.

This is a photo of my Bougainvillea that was brought indoors before the night temperatures were below freezing. As you can see, it lost its leaves in response to the cold weather.

Bougainvillea leaf drop.
New Leaves emerge after the leaf drops due to Winter. The Bougainvillea fully recovered.

I brought my plant indoors and placed it in a sunny south facing window in my kitchen. Why South facing? Well, do you remember we talked about recreating the natural conditions of the bougainvillea preferred habitat to help the leaves regrow? Our bougainvillea plants love full sun so always find a nice cool, sunny spot indoors.

But keep it away from radiators, as the fluctuating temperatures and dry air do not help your plant.

By bringing the bougainvillea indoors for Winter, I always find it suffers a degree of shock from being moved indoors from the cold outdoor temperatures to the comparatively warm indoor temperatures.

This can actually exacerbate the leaf drop but the bougainvillea cannot tolerate freezing temperatures and the leaves begin to grow again in the early Spring.

Once the night temperatures are consistently above 5°C (41°F) then you can place your bougainvillea outdoors again in a sunny location.

I did some testing over the years and found that it is better to place the bougainvillea outdoors for a few hours over the course of a week before leaving it outdoors so it has a chance to acclimate rather than just place it outdoors after a period of being indoors.

So if its a nice, sunny, warm day, place you bougainvillea outdoors but bring it back in overnight if the temperature is still too low at night.

With patience, new leaves on your bougainvilleas should emerge in the early Spring in response to warmer temperatures and more hours of light.

Top Tip: What I found really makes a big difference if the leaves drop over Winter, I to use a liquid fertilizer at half strength during the spring, as this gives the bougainvillea the nutrients it needs to grow its new leaves, which, as I’m sure you can appreciate, is quite an energy-intensive process.

Are you Watering Too Much? Over Watering Your Bougainvillea Causes The Leaf Drop

Bougainvilleas are native to hot and relatively dry areas of South America and thrive in similar climates such as the Mediterranean or California. (The best bougainvilleas I have ever seen were in Greece! Flowers everywhere and splendid fragrance!)

We need to remember that Bougainvillea has specifically adapted to environments with relatively low rainfall, therefore they are vulnerable to stress from too much moisture around the roots, which can be caused by:

  • Watering bougainvillea too frequently.
  • Growing bougainvillea in pots or containers with drainage holes in the base.
  • The use of trays or saucers under the pots prevents excess water from escaping.
  • High rainfall.

If your bougainvilleas roots stay in damp soil for too long, then the symptoms to look out for are the leaves turning yellow and dropping as a sign of stress.

Of course, you can easily pinpoint whether the problem is damp soil by feeling it yourself.

If the bougainvillea is consistently overwatered, this can cause fungal diseases such as root rot, which often kills the water-sensitive bougainvillea.

(If you think your bougainvillea is dying, read my article why is my bougainvillea dying to save it).

How to Save Bougainvillea with Leaf Drop Due to Overwatering (Step-by-Step)

  • Water less often! Bougainvilleas should be watered infrequently to emulate the conditions of their native dry environment. How do we do this? You should water bougainvillea when the soil feels dry to a finger’s depth. Typically, I water my potted bougainvillea every two weeks is a good balance for the bougainvillea water requirements and for allowing the soil to drain between bouts of watering so that the roots stay healthy rather than causing the leaves to drop. Bougainvilleas that are established in garden soil often only require additional water in times of exceptional drought.
  • Ensure that the pot or container has drainage holes so that excess water can escape after watering your bougainvillea. I know this may seem obvious, but you’d be amazed at the number of customers I talk to who have repotted their bougainvillea to a pot without drainage holes! Some decorative plant containers do not have any drainage holes which causes the soil to become saturated which mimics the effects of overwatering and causes the leaves to drop.
  • If you have placed any trays or saucers underneath your bougainvillea pot, empty them regularly so that water can escape and the soil can dry out between waterings.
  • High rainfall can also cause excess moisture around the roots of your bougainvillea, which can cause leaf drop. If you live in a climate with higher rainfall, like mine, it is a good idea to grow bougainvillea in pots or containers as they have more favorable drainage conditions than garden borders. Amend the potting mix with horticultural sand, grit, or perlite to help increase the drainage so that the soil does not stay damp for too long and cause the leaves to drop or root rot.

So, as I mentioned, I live in a climate with high rainfall (the Pacific Northwest), and I have some really great tips that help to mitigate the effects of rainfall and overwatering…

  1. Plant your bougainvillea in a clay or terracotta pot! Why? Because these materials are porous, it allows the soil to dry out more evenly around the bougainvillea roots, which reduces the risk of root rot and the subsequent leaf drop. Plastic and ceramic pots are impermeable, which means they retain moisture, which in a climate of high rainfall can mean the soil is too boggy for your bougainvillea.
  2. Use as much as 40% horticultural sand or grit in your potting mix when repotting bougainvillea. This helps to keep the soil nice and aerated, which improves how quickly it drains and creates the dryer soil conditions that your bougainvillea prefers. In my opinion, this makes the biggest difference in reducing the risk of root rot and helping the bougainvillea stay leafy.

By creating dyer soil and watering conditions that replicate the bougainvillea’s native environment, the soil has a chance to dry out somewhat between bouts of watering, which prevents stress on the plant and reduces the risk of bougainvillea losing leaves.

When I have had to do this for customers (I also work as a landscape gardener) the bougainvillea’s leaves do grow once the plant is happier, and the bougainvillea should also display more flowers in dyer soil.

We need to remember, If your bougainvillea is potted, always water generously but infrequently.

For example, it is most often best practice to water the pot with a soak once every two weeks in Summer rather than water lightly every few days.

This promotes proper root development so that the roots can access the water and nutrients they require for a healthy plant.

I always use my finger to judge whether the soil is dry or not, as I find it is more accurate than all the water gauges that I have tested, and it’s a lot easier.

(Read my article, how to water bougainvillea in pots).

Not Enough Sun Causes Bougainvillea to Lose its Leaves

Our bougainvilleas are actually vines that require full sun for the best display of flowers and the healthiest, most resilient plants.

If the bougainvillea is in too much shade, it has less energy to display flowers, and the leaves can turn yellow and drop off, which is contrary to the conditions to which it has adapted in its native environment.

Whenever you see bougainvilleas with a spectacular display of flowers and lots of leaves, they are located in areas with full sun. Remember how we talked about bougainvillea flowering at its best in the sunny Mediterranean countries? With warm temperatures, sunlight is directly correlated with flowers on display.

(There are several reasons why a bougainvillea drops its flowers so I wrote another article explaining why a bougainvillea is not displaying flowers and how to resolve the problem).

Therefore, it is important for your bougainvillea to be located in the sunniest part of your garden to prevent it from losing its leaves, so try to find a location with at least 6 hours of direct sun. Mine actually flowers best with 8 hours or more…

How to increase bougainvillea blooms
This is my gorgeous bougainvillea after it had dropped all its leaves and flowers the year before (due to cold temperatures). Look at it, flower now!

More sunlight also increases evaporation, which also contributes to the bougainvillea’s preferred dry conditions.

Whenever I have moved a Bougainvillea from a shady spot to a sunny spot, it has shown new growth in 3 or 4 weeks if it is during the Spring and Summer. If it is already Fall and Winter then you may have to wait until the Spring to see new green leaves emerge.

(Read my article, how to grow bougainvillea in pots).

Is Your Bougainvillea Losing Leaves After Planting? (Transplant Shock)

If your bougainvillea is losing its leaves after you have bought it from the garden center or nursery, or perhaps you have relocated when moving house,? If so, this is a sign of stress due to the contrast in conditions.

Our Bougainvilleas are fussy little customers, and they are sensitive to variations in sun exposure, temperature, airflow, and watering frequency.

When you buy a bougainvillea from a store, it is often cultivated in specific conditions of a commecial greenhouse with controlled sun, watering, fertilizer, and temperature, so when it is transferred to your garden, the change of conditions can cause shock, and the leaves (and flowers) to drop.

This has happened to me, and it is very common. However, do not be disheartened! I can tell you first hand that bougainvillea can recover from losing its leaves if it is cared for properly as it requires:

  • Full sun for flowering and retaining its leaves.
  • Warm temperatures. Bring your bougainvillea indoors for protection from freezing temperatures (bougainvilleas should be grown in pots and containers in cold climates).
  • Watered infrequently. (Typically, the bougainvillea should be watered once every two weeks or when the top two inches of the soil are dry.)

By following these best care practices, you can mitigate the risk of the bougainvillea losing its leaves.

In my experience, It may take some time for your bougainvillea to acclimate to its new surroundings, but it should begin to grow new leaves if it is happy in its surroundings. When this happened to me, it took 3 weeks in the Spring and Summer (In May and June) to start to grow its leaves. The following year, my bougainvillea flowered beautifully.

Did you know that in the right climate (Mediterranean climate), your bougainvillea can bloom all year round? Outside of these warm climates, you typically get a classic seasonal cycle of flowers in Spring and summer, with few in Fall and Winter.

I would not recommend fertilizing your bougainvillea straight after it has dropped its leaves. The plant is in a state of stress, and any additional fertilizer can potentially harm it.

I personally waited to see new green leaves emerge. This was an indication that the bougainvillea had acclimated to the conditions. Once the leaves started growing back, I applied a half-strength regular fertilizer once per month in the spring and summer, and my bougainvillea was very healthy with all its leaves and flowers.

Do you have any insights into caring for bougainvillea? Or do you have any more specific questions? Please leave a comment below, and I’ll reply! I love hearing from you all!

Key Takeaways:

  • The most common reasons bougainvilleas lose their leaves are cold temperatures and overwatering. Bougainvilleas are native to hot and dry climates, so they drop their leaves as a sign of stress caused by too much moisture around the roots caused by overwatering and cold weather.
  • Bougainvilleas can also drop their leaves if they are moved or shortly after you bought them. Leaf drops can be a sign of stress due to the contrast in temperatures, sunlight, and watering frequency of the nursery where they were cultivated before sale and the conditions of your garden.
  • Bougainvilleas are native to sunny climates, where they thrive in direct sunlight. If they are in too much shade, the flowers and leaves often drop.
  • To save a bougainvillea after losing its leaves, it is important to replicate the conditions of its native environment by watering it less frequently, locating it in full sun, and protecting it from cold temperatures.

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