Bougainvillea leaves turning yellow is the plant’s way of informing you that it is experiencing some kind of environmental stress that needs to be addressed and remedied.
The most common causes of yellowing bougainvillea leaves are overwatering, underwatering, insufficient light, transplant stress, temperature changes, lack of nutrients, and pests.
In this article, we will discuss the different causes of yellowing bougainvillea leaves and how to remedy each one.
The Bougainvillea Plant
Bougainvillea plants are sometimes referred to as flowering machines because of their many brightly-colored flowers and green leaves. They can grow up to 40 feet tall, and there are over 300 species of bougainvillea all over the world, thanks to botanists interbreeding the original 18 species.
They have heart-shaped leaves and vibrant flowers. The inner flower has four to six bracts, which may be yellow, purple, red, orange, white, or pink. They bloom in the spring and summer, which makes this plant great for summer landscapes in your garden. They are often planted in hanging baskets, containers, or along walls and fences.
Why are the leaves of my bougainvillea turning yellow?
Watering issues
The most common cause of yellowing bougainvillea leaves is either overwatering or underwatering. Both can cause water stress to the plant resulting in leaf discoloration.
Overwatering drains the green color from the bougainvillea leaves because the soil is soggy and the roots are drowning. The plant is then unable to effectively transport nutrients from the soil into the plant. You need to make sure the plant’s soil has good drainage. The excess water from rain or your overwatering should be able to seep through the soil easily and not cause it to become waterlogged. You can add compost or peat moss to the soil to improve its drainage.
Underwatering can also cause yellowing of the leaves because you are depriving the plant of the moisture it needs to survive. If you notice the leaves on your plant are turning yellow and wilting, it is probably underwatered.
Bougainvillea plants need water not only to avoid dehydrating, but also as a means of transporting the nutrients from the soil into their roots. If there is no water, they will have no nutrients.
The natural habitat of these plants are the tropics and subtropics, where they get plenty of water. If you live in a place with a mostly dry climate, you need to water the plant more frequently in order to emulate its natural habitat.
Insufficient light
Another reason your bougainvillea leaves are turning yellow could be insufficient sunlight. Bougainvillea plants need at least six hours of sunlight per day in order to be healthy. Remember these are naturally tropical plants, which means that they are adapted to living in places that get plenty of sun all year round. Make sure you place your plant in a spot in your garden that provides it with enough light. If the plant is indoors, place it near a window that takes in plenty of light, and be sure to rotate the plant every few days so that all sides of the plant get their day in the sun.
If you take your plant inside the house during the winter, make sure you provide it with a grow lamp so that it still gets light despite the gloomy weather.
Transplant stress
If you have just moved your bougainvillea inside the house for the winter and the leaves have started to turn yellow, this may be due to transplant stress. Any change to the plant’s environment can cause stress, especially if the plant has become accustomed to living in certain conditions. This is completely normal and the best you can do is to make the transition as easy as possible on the plant by ensuring the place you are transferring it to has the same conditions.
Try to temper the stress by gradually moving the plant to its new location. You can take the plant indoors for a few days, then take it back outside for several days. Keep repeating this until the plant has adjusted to the inside of the house.
Do not overwater or give fertilizer to your plant after transplanting or moving it.
Lack of nutrients
Like most plants, bougainvillea needs to be fertilized regularly in order to keep blooming and keep its leaves vibrant.
If your plant has yellow leaves, it could have a magnesium or iron deficiency. You can correct this by using a fertilizer designed specifically for bougainvillea plants. You can also make your own solution by mixing a tablespoon of Epsom salts to a gallon of water and then applying the solution to the plant’s soil. This will help enhance the soil’s iron and magnesium content.
If the plant’s yellow leaves are also twisted, it might have a zinc deficiency. You can use a fertilizer with chelated zinc to correct this.
Temperature changes
As mentioned above, bougainvillea plants are tropical and are often found in coastal areas. They can survive in colder regions, but they will need to be provided with as many simulated tropical living conditions as possible.
Your bougainvillea plant will struggle in cold temperatures, especially in the winter. One of their reactions to this stress is the yellowing of their leaves.
You can lessen the risk of damage to your plant due to cold temperatures by placing it in a warm location. If you need to buy a grow lamp for the plant, then do so. The closer you are able to replicate the tropical setting of the plant’s natural habitat, the better.
Pests
Bougainvillea plants can get attacked by pests like spider mites. These insects feed on the leaves of the plant and deplete its nutrients. The more spider mites there are on a plant, the faster the leaves will turn yellow. Signs of spider mites on a bougainvillea plant include moving dots on the leaves, and webs.
You can get rid of these pests by spraying the plant with water jets every two weeks to dislodge the spider mites. You can wipe down the leaves with neem oil to kill the pests. Apply the neem oil once a week for a month to make sure all the mites are eradicated.
What should I do about the yellow leaves on my bougainvillea plant?
Yellow leaves no longer play a role in photosynthesis, and thus will not be able to produce any energy or food for your plant. They are just using up energy and resources that may be needed by new leaves.
The best thing to do is remove them to save the plant’s energy. Pruning also makes the plant look much prettier.
Conclusion
Bougainvillea leaves turn yellow when they are experiencing some type of environmental stress. In order to correct this change in color, you will need to identify what exactly is causing the discoloration.
The most common causes of yellowing bougainvillea leaves are overwatering, underwatering, insufficient light, transplant stress, temperature changes, lack of nutrients and pests.
Image: istockphoto.com / Bigpra