When left unattended, bougainvillea plants can quickly take over your garden or yard. To kill a bougainvillea plant, you need to trim as many thorny vines as possible to reach the trunk.
Cut the trunk down to the stump. Use a chainsaw or a hatchet to cut the plant down to its stump if dealing with a large, thick plant trunk.
Use the Foliar Method to kill bougainvillea plants. The Foliar Method requires the direct application of an herbicide to the trunk or leaves of the plants.
Use a paintbrush to apply a liquid herbicide all over the trunk. Check the stump every few weeks for new growth and reapply the herbicide as necessary. After a few months, pull or dig the plant trunk out of the ground to remove the root ball.
Characteristics of Bougainvillea Plants
Considered a vining shrub, the bougainvillea plant produces small white flowers surrounded by brilliantly colored leaves called carpals. These carpals turn bright pink, purple, red, yellow, magenta, and white when flowering.
But while bougainvillea plants add color to any garden, they also have very sharp thorns that can easily cause injury.
Homeowners use bougainvillea plants to cover walls, and they provide a decorative cover for yard structures such as pergolas and gazebos. Some homeowners even use bougainvillea plants as security fences because of the thorny vines.
Is Bougainvillea Poisonous?
Some people experience blistering, itching, burning, swelling, and sores after coming in contact with the long thorns and the sap found on the vines of the bougainvillea plant.
Avoid planting a bougainvillea in high-traffic areas to prevent people from coming in close contact with the thorns and the sap.
How to Use the Foliar Method to Remove Bougainvillea Plants
To effectively eliminate a bougainvillea plant using the Foliar Method, you need to consider:
- Time of year – wait until late summer or fall to apply a liquid herbicide. Water the bougainvillea beforehand to ensure the herbicide travels throughout the plant after absorption.
Since bougainvillea plants require very little water to survive, the plant may seem unaffected by the herbicide at first. You may need to apply the herbicide a few times to kill the plant.
- Herbicide concentration – in most cases, an herbicide with a 1 to 2 percent concentration should kill a bougainvillea plant without much effort.
If you use an herbicide with too high a concentration, you will destroy the plant’s conducting tissue before the herbicide has a chance to reach the roots. Failure to reach the roots could result in regrowth because the roots remain alive.
What to Do with a Thick Bougainvillea Trunk
Some bougainvillea plants have very thick trunks. If you can’t cut the plant trunk down to a stump, consider injecting the trunk with an herbicide instead. After removing the vines, use a hatchet to make several deep cuts into the trunk. Use a spray bottle to saturate the plant trunk with herbicide.
What to Do After Applying an Herbicide
After applying the herbicide, monitor the trunk for regrowth. Spray new Bougainvillea leaves with the herbicide to prevent further growth.
It would be best to wait a few months before removing the stump to ensure that the herbicide worked its way down to the roots.
Dig the stump and Bougainvillea roots out of the ground once you’re sure that the plant is no longer alive. Try to remove the entire root structure to ensure regrowth does not occur.
Bougainvillea Removal Methods to Avoid
The best method for removing a bougainvillea plant from your garden requires an herbicide that you spray, paint, or inject into the plant trunk.
Heavy-duty plastic or fabric root barriers can help stop root growth but will not aid in killing the bougainvillea. Over time, the roots will weave their way underneath or break through the barrier. Use this method if you want to control the growth; rather than eliminate the plant.
Burning the vines will not prevent resprouting. Burning bougainvillea vines may encourage growth rather than prevent it. Also, a controlled burn can quickly become an out-of-control burn if you’re not careful.
Related Bougainvillea Topics
How to Tame Overgrowth
If you decide to keep your bougainvillea plant, frequent pruning can help keep the plant from growing too large.
Always wear long pants, a long-sleeved shirt, and gloves when pruning this plant to prevent the thorns from poking your hands, arms, and legs. Protective coverings also help keep the sap from making contact with your skin.
Use a pair of sharp hand pruners or cutting shears to shape your bougainvillea plant to suit your garden. Carefully remove the cut vines and dispose of them in a safe place away from people.
Prune your bougainvillea after the plant flowers – in the early spring, late winter, or at the beginning of the rainy season. Pruning in the late summer or early fall may reduce flowering.