With long-lasting blossoms and an exotic look, the yellow oleander is a highly ornamental plant that’s grown despite it being a poisonous plant.
Thevetia peruviana is considered a tall growing shrub that’s native to Central America and Mexico.
As you’ll see in the plant care tips I’ve put together below, the yellow oleander is a relatively resilient plant, except for when it comes to particularly chilly winters.
Yellow Oleander Plant Care Tips
Here’s a quick primer on the basics of yellow oleander plant care:
The Cascabela thevetia plant is a slender-looking plant with thin leaves and bright yellow or orange flowers.
The plant reaches 7-10 feet in height. Leaves are 4-5 inches long and ¼ inch wide. Its trumpet-shaped flowers are about 2-3 inches large.
The plant needs a fair amount of space to grow and expand.
With yellow oleanders you want to maximize sun exposure, especially if you’re growing this plant indoors.
For best results, place the shrub near a south-facing or a west-facing window.
Outdoors, you can allow the plant to grow in full sun or partial shade.
The yellow oleander is a thirsty plant, so regular watering is essential, especially during early spring to early fall.
Thorough watering is even more essential during the blooming period. If the soil dries out in this time, the blooms will wither away.
Cut back on watering during the cold season.
Temperature & Humidity
The yellow oleander does great at room temperature conditions and it’s cold hardy down to 25 F.
The yellow oleander will appreciate misting, especially when the air becomes too dry.
Misting the plant or otherwise increasing humidity around it will help the plant stay in top shape when the air in your home becomes too dry.
The Thevetia peruviana is not particular about its soil type. When grown indoors, however, pick a fast-draining soil that provides aeration and prevents root rot.
Use regular potting soil in combination with peat moss and compost for a lighter soil that offers better drainage.
You should start feeding the plant when you notice buds appearing, usually in early spring. Stop feeding in fall and winter.
The yellow oleander is a high water user and can benefit from regular feeding. Use a complete fertilizer and feed every 6-8 weeks.
Potting & Repotting
Because this plant does not grow too tall, neither too fast, repotting every 2-3 year is enough.
Use a slightly bigger pot when repotting and follow the same recommendations for soil type.
Make sure to schedule repotting to early March, just when the plant is beginning its active growth.
Yellow Oleander Plant Propagation
To propagate your Cascabela thevetia, choose non-flowering stem cuttings.
Choose a cutting that’s 4-5 inches long and dip the tip in rooting hormone.
Use regular potting soil for rooting, and keep in a warm place with lots of sunshine.
You can also cover the plant tray with a plastic wrap.
In a few weeks, your yellow oleander stem cutting should grow roots.
Yellow Oleander FAQs
Clearly, the yellow oleander is not a fussy plant and can make a good beginner-friendly plant with a few caveats that I discuss in the FAQs below.
Is the Yellow Oleander Toxic?
The yellow oleander is a highly poisonous plant both for humans and pets.
The sap of the leaves and stems are also toxic to anyone handling the plant.
All parts of the plant are toxic — including flowers — so if you have pets or small children, you need to be very careful about keeping this plant in or around the house.
Is the Yellow Oleander Prone to Pests or Diseases?
The yellow oleander is fairly resilient when it comes to pests or diseases, but there are a few things you should watch out for nonetheless.
Scale and mealybugs are the most common pests to take up residence on your yellow oleander and damage the leaves if they’re left unchecked.
Mealybugs will leave cottony spots on the leaves while scale will leave brown spots on the underside of the leaves.
Scale insects can be removed by either wiping the leaves with a damp cloth or spraying the plant with neem oil.
Mealybugs are easiest to remove by using a cotton disk dabbed in rubbing alcohol.
You may encounter flowering issues if the plant gets too little light, or leaves may turn yellow and buds may fall off if the plant is exposed to cold temperatures.
Does the Yellow Oleander Need Grooming?
As a low maintenance plant, the yellow oleander will not need regular trimming or pruning.
That said, you can cut back a yellow oleander in the fall to get it back to a manageable size. You can also cut non-flowering stems.
Given the plant’s highly poisonous nature, make sure you wear protective gloves when handling the plant in any way, even if you’re just repotting.
The sap of the leaves and stems can cause skin irritations and rashes, so best to avoid any skin contact.
Is the Yellow Oleander a True Oleander?
Despite the name and resemblance, the yellow oleander is not a true oleander. It’s part of a different genus than true oleanders.
True oleanders are part of the Nerium genus and have different keeping requirements and they’re drought-resistant.
That said, both plants are extremely poisonous, so it’s best to avoid planting either of them near pavements, playgrounds or other play areas.
The yellow oleander is widespread as an ornamental plant that’s enjoyed by gardeners for its slender shape, vibrant and delicately fragrant flowers that grow abundantly.
In spite of its toxicity, this plant can be kept indoors or out with the general caveat that children or pets should not have access to the plant.
Other than this, the plant has high watering requirements and enjoys sun exposure, although it can tolerate semi-shade as well.
With these in mind, the yellow oleander plant is suitable for beginner gardeners who want to add an exotic plant to a terrace or balcony.