Known for their lush foliage and vibrant bursts of color, Bougainvilleas (often called paper flowers) are the crown jewels of any sunny garden. But if your plant starts dropping leaves right in the middle of its blooming season, it’s more than just a mess—it’s a sign that your plant is struggling. You’ll want to take leaf loss seriously and act fast to get your beauty back on track.
Common Causes
There are a few usual suspects when it comes to a Bougainvillea losing its leaves:
- Not enough light
- Dehydration (Drought stress)
- Waterlogging (Soggy roots)
- Nutrient deficiency
- Natural winter dormancy
- Pests and diseases
Not Enough Light
Bougainvilleas are total sun-worshippers. Honestly, they can’t get enough of it. If the spot is too shady, the plant will get “cranky” and start dropping leaves to show its displeasure.
What to do
- Move your Bougainvillea to the warmest, sunniest spot you have.
- Ideally, place it on a balcony with a southern exposure.
- If you’re keeping it as a houseplant, a bright south-facing window is a must.
Drought Stress
This usually happens during the peak of summer. Because of that dense canopy of leaves, the plant loses moisture incredibly fast through evaporation when it’s hot out. If the soil dries out completely, the plant goes into survival mode and sheds leaves to prevent further water loss.
What to do
- Emergency First Aid: If your potted Bougainvillea is bone dry, dunk the whole pot into a bucket of lukewarm, soft water. Keep it submerged until the air bubbles stop rising.
- Going forward: Increase your watering schedule. Try watering from the bottom (using a saucer) to give you better control over how much the plant is drinking.
Waterlogging (Soggy Feet)
While drought is bad, “wet feet” are actually much more dangerous. If the soil stays constantly saturated, the roots will begin to rot. Once the roots are damaged, they can’t send water up to the rest of the plant, causing the leaves to fall off. This is a serious red flag.
What to do
- Repot your Bougainvillea immediately into fresh, well-draining soil.
- Carefully trim away any mushy or rotten roots before replanting.
- Make sure to scrub the pot thoroughly with hot water before reusing it to kill off any lingering fungi.
Nutrient Deficiency
To keep up that spectacular growth and flower production, Bougainvilleas need a lot of fuel—way more than what’s typically found in a standard bag of potting soil. Once those nutrients are tapped out, the leaves will start to drop.
What to do
- Give your plant a dose of fertilizer right away.
- To keep it healthy, continue fertilizing regularly through mid-to-late August.
Winter Dormancy
Since conditions aren’t exactly tropical during the colder months, it’s perfectly normal for a Bougainvillea to lose some leaves while in its winter quarters.
What to do
- Let the plant rest; this is its natural cycle.
- Scale back on watering even more (the risk of root rot is higher in winter).
- Stop fertilizing entirely until spring.
Pests and Diseases
Of course, diseases and pests can also cause leaf drop. If you spot an infestation or strange spots, isolate the plant from your other greenery, give it a good pruning to remove the affected areas, and start an appropriate treatment immediately.
