The bougainvillea is the national flower of Grenada, which is popularly grown in warm climate countries across the world.
They are categorized as evergreen climbers, typically flowering from summer to autumn. They are a great addition to any garden, boasting a plethora of brightly saturated blooms.
Most believe that it is the flower itself that gives off this tropical appeal, but it is in fact the bract around the bloom that holds such bright colors.
But what if your bougainvillea isn’t blooming, and you are missing out on this tropical experience?
Read further to find out why!
Why is my bougainvillea not blooming?
There are several possible reasons for a bougainvillea not to bloom. It’s likely to have something to do with the way you have been handling and maintaining your plant. Although the bougainvillea is very hardy, they are also very sensitive to change. Environmental factors such as not getting enough sunlight paired with overwatering or over-fertilization are likely to be the causes of this problem.
Bougainvillea fall under the USAD hardiness zone 9b and 10. This means that they need at least 6 hours of sunlight daily, and find direct sunlight and warm conditions most favorable.
Many make the mistake of placing a bougainvillea in a shady or neglected area of their garden to try and brighten it up.
However tempting this might be, the bougainvillea does not thrive in shade at all. Warmer and almost tropical climates will prevent any disturbance to their blooming cycle.
A temperature of around 59 degrees Fahrenheit (15 degrees Celsius) during the night is perfect for a bougainvillea.
If temperatures drop too low (anything under 42 degrees, 6 degrees Celcsius) your bougainvillea will enter dormancy, meaning that their leaves will drop and die.
During the fall and winter seasons, dormancy in bougainvilleas is normal and is a way of protecting themselves from colder weather.
However, if the weather remains cold for too long or dormancy occurs out of regular seasons it can lead to death.
Many think that because the bougainvillea enjoys lots of light and direct sunlight they must also need a lot of hydration.
This is not the case, as these plants are actually very hardy when it comes to their preferred environment. It’s almost as if they need to be neglected and left alone to truly thrive!
You should think of your bougainvillea as having similar temperaments to a cactus or other drought-resistant plants like lavender.
It is recommended to at most water bougainvillea every fortnight. The soil should be completely dry in between watering sessions.
A touch test is the best way to see if you’re overwatering your bougainvillea. 5 days after watering, press your fingers to the soil to detect any moisture.
If the soil is still moist or wet then you are definitely giving your bougainvillea too much water and you should change your watering schedule immediately.
If your plant receives too much moisture for a long period of time this can lead to root rot and other similar fungal diseases.
Too much fertilizer
Over-fertilizing is another common reason for a bougainvillea not blooming.
If your bougainvillea has branches filled with lots of green leaves but there are no signs of flowers blooming, you are likely using a nitrogen-heavy fertilizer.
Nitrogen-based fertilizers should only be used if the leaves on your bougainvillea are looking drab and discolored.
Your bougainvillea should only be fertilized every 4-6 weeks, and even then a simple tablespoon amount is sufficient.
Ensure that your chosen fertilizer contains both phosphate and potassium, as these are the nutrients that bougainvillea are most reliant on. Many even use hibiscus plant fertiliser.
Top tip – adding a tablespoon of Epsom salts when you fertilize your plant will add extra magnesium, which will, in turn, increase its intake of most needed nutrients.
Plant shock is trauma that your plant experiences after a change in location or environment. This results in leaves wilting and dying, and no new growth or blooms appearing for up to 3 months.
Although bougainvilleas are very tough plants, they have particularly fragile root systems.
Transplanting a bougainvillea without paying full care and attention to its roots can cause plant shock.
Although plant shock is not irreversible, with lots of direct sunlight and very occasional watering, it’s probable that your bougainvillea will begin to thrive once again after 1-3 months of recovery.
You can tell the difference between a dead bougainvillea and one that is in shock by gently bending its stems.
If the stems are bending and have a sort of resistance, that means your plant is still alive. However, if the stems feel brittle and snap very easily it is likely that your bougainvillea sustained too much damage.
Pruning your plant back during the summer months could result in cutting off all of the new growth buds, meaning that there will be no growth for flowers to bloom from.
If your bougainvillea is growing to undesirable lengths, be sure to trim or prune its stems and leaves during early spring, before any sign of budding growth has appeared.
If your Bougainvillea leaves are turning yellow, read our specific guide.
Frequently Asked Questions about Bougainvilleas not Blooming
Is it possible to under-water a bougainvillea?
Although rare, it is possible in climates with almost no rainfall. If the soil is bone dry and the leaves are beginning to have slight wilt, then that is a calling for your bougainvillea to be watered.
Can you grow a bougainvillea in a greenhouse?
Bougainvillea can be grown in a greenhouse as long as they are still receiving an adequate amount of sunlight. Greenhouse-grown bougainvillea will need much less water, as these plants do not like to be moist.
Marcel runs the place around here. He has a deep passion for houseplants & gardening and is constantly on the lookout for yet another special plant to add to his arsenal of houseplants, succulents & cacti.
Marcel is also the founder of Iseli International Commerce, a sole proprietorship company that publishes a variety of websites and online magazines.