Why is Bougainvillea Dying?

A dying bougainvillea can be caused by overwatering, slow drainage soils, and low temperatures. Too much moisture around the roots can cause leaf drop and root rot. Temperatures consistently colder then 40degF (5degC) result in dying bougainvillea.

Bougainvillea leaves can also fall after being planted due to transplant shock, or simply because they aren’t in full sunlight.

Continue reading to learn more about why your bougainvillea has died and how you can revive it

Bougainvillea

Bougainvillea Dying after Planting (Transplant shock )

If your bougainvillea drops leaves and flowers immediately after being planted, it is likely that the plant has experienced shock from a sudden change in its growing environment.

Bougainvilleas can be grown commercially in greenhouses to be sold in garden centers. They can be kept at constant temperatures and can be watered regularly. The roots can then become accustomed to the soil conditions.

Bougainvillea may become less resilient to changes in weather conditions if they are exposed to constant conditions.

They are often transplanted in different conditions than their usual environment when they arrive at a garden center.

Transplant shock can result in leaf and flower loss from your bougainvillea, and may appear to be dying.

However, shock can occur and plants can adapt to their surroundings as long as they are properly cared for.

To reduce the impact of transplant shock, it is important that bougainvillea have …

  • Full sun (at least 6 hours).
  • Well draining soil (approximately 80% compost with 20% sand or grit). If necessary, amend the planting area or prepare a well-draining potting mix (approximately % compost with % sand or grit. Pots should have drainage holes in their base.
  • Watered at a frequency that allows the soil to dry out between bouts of rainfall or watering (once every two weeks is typically a good guide but adjust watering frequency according to your climate and rainfall). To help the bougainvillea establish itself and reduce shock, give it a good soak.
  • Plant it in a pot or container and take it inside if the temperature is as low as 40degF (5degC).

The bougainvillea is able to recover from transplant shock by meeting all its growing needs.

It may take some time for the plants to adjust to their new environment. Bear in mind that just because leaves are falling does not mean they are dying.

Overwatering Bougainvillea Causes root Rot

Overwatering is the most common reason bougainvilleas are dying.

Bougainvilleas, which are natives to dry areas in South America , thrive in gardens that mimic their preferred dry conditions.

Bougainvilleas that are overwatered often show signs of stress like leaf drop and lack of flowers. Overwatering can lead to rootrot , which is often the cause of a dead bougainvillea.

Gardeners often mistake leaf fall for a sign that the bougainvillea needs more water, which can lead to further problems.

If you water your bougainvilleas more than once per week, you may be overwatering.

Only water bougainvilleas if the soil has dried slightly since your last watering or after rain to ensure that the soil doesn’t remain damp. Boggy soil is not their preferred conditions.

The amount you water your bougainvillea will depend on many factors such as the climate, rainfall, sun exposure, soil drainage speed, etc. It is crucial to water your bougainvillea in accordance with the weather and climate conditions.

To determine if there is moisture in the soil surrounding the bougainvillea, you should test it to the depth of your fingers.

If the soil is still moist, you can skip watering for a few more days to make the soil dry. Then give the roots a good soak to help them grow and establish themselves in the soil. This will increase its drought resistance and hardiness.

‘ Typically, bougainvilleas thrive when they are watered every two weeks if there have been no significant rains and planted in well-draining soil .’

This is especially true for bougainvilleas that are planted in containers. It provides enough moisture to allow the plant to thrive, but also enough time to dry the soil out to prevent the roots from becoming water stressed.

I must reiterate that it is crucial to water according the climate. Established bougainvilleas are more tolerant to high rainfall than those that don’t require additional water.

If your bougainvillea has stopped growing or is showing signs of decline, reduce the frequency of watering to once per two weeks. Only water it if it hasn’t rained heavily.

The bougainvillea will show signs of improvement if the temperature is high and it is in full sunlight. If it is suffering from water stress, it should be able to recover within the next few days.

This is dependent on whether bougainvillea was planted in well-draining soil or in a container with drainage holes at the base.

However, if the bougainvillea is left in saturated soil for too many days it could have root rot. The plant may die.

(If your bougainvillea has lots of foliage but not flowering read my article why is my bougainvillea not flowering? )

Slow Draining Soils. (Bougainvillea) Good Drainage )

Bougainvilleas prefer soil that is light and porous to allow water to drain from roots. This prevents root rot.

A bougainvillea should only be planted in soil that contains organic materi (compost, leaf mould), and some inorganic material (horticultural soil sand or grit) to improve drainage and aeration. This will replicate the soil conditions found in the native environment.

Bougainvilleas are not able to grow in slow-draining soil, such as clay or naturally boggy places. This can lead to water stress and water pooling around roots.

The signs that a bougainvillea is suffering from slow draining soils are similar to an overwatering. Leaf drop is the first sign, despite mild or warm temperatures. (Leaves can also fall due to cold).

How it can be solved:

  • If at all possible I would strongly advise to avoid planting bougainvillea in clay soils as it is unlikely to live for very long.
  • In gardens with heavy clay or naturally boggy areas it is best to grow bougainvillea in pots, containers or raised beds due to the more favourable drainage conditions. It is easier to adjust the soil profile to meet the needs of bougainvillea.
  • In soil that is consistently damp (due to slow drainage) transplant the bougainvillea to a pot or dryer area of the garden as a matter of urgency. To protect the delicate roots of bougainvillea, use a fork instead of a shovel or spade when digging.
  • Choose a pot that is around 12-16 inches across with lots of drainage holes in the base and use a potting mix of approximately 80% multi purpose compost to 20% horticultural sand or grit to improve drainage.

There are best practices that you should know before transplanting bougainvillea. I recommend this YouTube video:

 

Bougainvilleas can tolerate roots being bound in a pot and this is even associated with more flowering. Root stress can promote flowering, but a larger container or pot has more soil capacity which insulates cold sensitive roots in cooler environments. A large container or pot is often a better option.

I would add more sand to my potting mixture in areas with more rainfall to make sure the roots dry faster and prevent root rot.

If the bougainvillea is too large to move, I suggest creating channels with a fork in the soil around it and adding sand (preferably with a funnel). This will change the soil profile and structure and improve drainage.

This tactic is surprisingly effective and can improve drainage to prevent bougainvilleas from dying.

In cooler climates with higher rainfall, more soil containing sand, gravel or perlite will increase drainage to counteract water. This helps prevent root rot and water stress.

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

Bougainvillea Leaf, and Flower Drop Due to Cold Temperatures

Bougainvillea can be found in hot, sunny and dry regions of South America. therefore it is relatively cold sensitive (hardy in USDA zones 9).

Bougainvillea can drop its leaves if it is experiencing stress in colder climates or when temperatures fluctuate significantly.

The colourful bracts (which are actually specialised leaves) that surround the flowers may also wilt or drop off as a reaction to the cold.

Some varties can tolerate cold better than others, with some even able to withstand a light frost and returning strong when the weather warms back up.

Bougainvillea can be deciduous in colder climates, and evergreen in warmer climates that are close to their native climate. So leaf drop does not necessarily mean that the plant has died.

Bougainvillea can be affected by a light frost. The leaves, flowers and branches may drop if they are subject to a slight freeze.

However, the older wood is more resistant and the roots (which are most sensitive to cold) are often able to survive as long as the soil insulation protects them.

If the bougainvillea is left to die from a hard frost or prolonged cold, it is more likely that they will not recover.

The best practice for growing bougainvilleas in cold climates is to plant them in pots and bring them indoors as soon as the temperature at night is below 40degF (5degC) (and place the pot in a sunny window) to prevent the bougainvillea from suffering in the cold or dying.

If you bring your bougainvillea indoors during Winter, water it about once every 4-6 week.

Place the bougainvillea where there is a steady temperature. This could be a garage or heated greenhouse.

Place the bougainvillea outdoors in full sun when the temperature at night is reliably more then 40degF (5degC) the following Spring.

Not enough sun-dying Bougainvillea

In their native range bougainvilleas enjoy full sun.

The amount of sunlight is the one most important factor for the health and life span of bougainvillea and it is directly correlated with the number of flowers it can display.

*Bougainvilleas need at least 6 hours of direct sunlight per day in Spring and Summer to thrive and produce flowers. They will not live long if they have too much shade.

Direct sunlight also increases evaporation in the soil, which creates the dry conditions to which bougainvillea are accustomed.

If your bougainvillea does not receive full sunlight, you can create more light by trimming back the surrounding vegetation or thinning any trees that may be shading it.

Another option is to transplant bougainvillea to a more sunny location if it’s possible.

A container or potted bougainvillea is a great option, as it can be moved easily to the full sun.

If you move the bougainvillea into a sunny area in your garden, it will show signs of recovery within a few weeks. However, if it is left in shade for too long, it may be difficult to revive.

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

 

Key Takeaways

  • The most common reasons for dying bougainvillea are over watering, boggy soil, cold weather and not enough sun. Bougainvilleas can be killed by frost, but they are not hardy enough to withstand cold. Root rot can be caused by overwatering or slow drainage soils. This results in a dead bougainvillea.
  • Bougainvilleas should be planted in pots or containers and brought indoors over Winter when the temperature is as low as 40degF (5degC).
  • Always plant bougainvillea in full sun. If bougainvillea is in shade, move it to a sunny spot. This can cause the plant to die.
  • Transplant shock can cause the plant stress. You should ensure bougainvillea gets enough sun, is well drained and has grit or sand.
  • Bougainvillea prefer dry conditions. The plant can be killed by overwatering or slow drainage soils. Water bougainvillea only after the soil has dried between waterings or rainfalls.
Stephanie

Stephanie

Went from a bad gardener to a half-decent one over 10+ years. Super happy to share my tips and tricks with you :)