Contents
Description
Thevetia is a genus of flowering plants in the family Apocynaceae. It comprises around 10 species of evergreen shrubs or small trees. The plants are native to tropical and subtropical regions of the Americas, from the southern United States to northern Argentina. Thevetia species are commonly known as yellow oleanders, despite not being related to the true oleander genus.
Taxonomic Information
| Domain | Eukaryota |
| Kingdom | Plantae |
| Phylum | Spermatophyta |
| Class | Magnoliopsida |
| Order | Gentianales |
| Family | Apocynaceae |
| Genus | Thevetia |
Appearance
Thevetia plants typically grow up to 6 meters tall, with a spread of 3 meters. They have a dense, rounded crown and a straight trunk with grey-brown bark. The leaves are glossy, dark green, and lanceolate in shape, measuring up to 15cm long and 5cm wide. The flowers are trumpet-shaped, with five petals that are yellow, orange, or pink in color. The fruit is a woody capsule, 4–6cm long and 2–3cm wide, containing up to four seeds.
Care Guide
Water
Thevetia plants prefer well-drained soil that is kept moderately moist. They do not tolerate waterlogged conditions, so avoid overwatering. In periods of drought, water the plants deeply once a week.
Fertilization
Thevetia plants benefit from regular fertilization during the growing season, using a balanced fertilizer with equal parts nitrogen, phosphorus, and potassium. Apply the fertilizer every two weeks, following the manufacturer’s instructions.
Soil
Thevetia plants prefer well-drained soil that is slightly acidic, with a pH between 5.5 and 6.5. The soil should be rich in organic matter, such as compost or aged manure.
Sunlight
Thevetia plants require full sun to thrive, as they are native to tropical and subtropical regions with high levels of light. They can tolerate some shade, but too much shade can reduce flowering and growth.
Hardiness Zones
Thevetia plants are hardy in USDA zones 9–11, which correspond to minimum temperatures of 20–40°F (-6.7 to 4.4°C). In colder regions, they can be grown as container plants indoors or in a greenhouse.
Common Pests & Diseases
Thevetia plants are relatively pest and disease-resistant, but they may be susceptible to the following issues:- Scale insects: These small, oval insects attach to the leaves and stems of the plant, sucking sap and causing yellowing and stunted growth. Use an insecticidal soap or oil to control infestations.- Spider mites: These tiny, reddish-brown pests spin webs on the undersides of leaves, causing yellowing and leaf drop. Use an insecticidal soap or oil to control infestations.- Leaf spot: This fungal disease causes brown or black spots on the leaves, which can lead to defoliation. Remove infected leaves and apply a fungicide to prevent further spread.
Habitat
Thevetia plants are native to tropical and subtropical regions of the Americas, including Mexico, the Caribbean, and South America. They grow in a variety of habitats, including open woodlands, scrublands, and disturbed areas such as roadsides and pastures. The plants are commonly cultivated as ornamentals in gardens and parks, as well as for their medicinal properties.
Question and Answer
Q: Are Thevetia plants toxic?
A: Yes, all parts of Thevetia plants are highly toxic if ingested, containing cardiac glycosides that can cause serious health issues such as vomiting, diarrhea, and irregular heartbeat.
Q: Can Thevetia plants be pruned?
A: Yes, Thevetia plants can be pruned to shape and control their size. Prune in late winter or early spring before new growth begins, using sharp, clean pruning shears.
Q: Do Thevetia plants attract pollinators?
A: Yes, Thevetia flowers are pollinated by bees, butterflies, and other insects, which are attracted to their bright colors and sweet fragrance.
Q: Can Thevetia plants be grown in containers?
A: Yes, Thevetia plants can be grown in containers as long as they have well-draining soil and receive full sun. Choose a pot that is at least 45cm wide and 60cm deep to accommodate the plant’s root system.
Related Plants
– Nerium oleander (Oleander)- Plumeria spp. (Frangipani)- Adenium spp. (Desert rose)- Allamanda spp. (Golden trumpet)- Catharanthus roseus (Madagascar periwinkle)
References
– “Thevetia peruviana.” Missouri Botanical Garden. Accessed March 22, 2021. http://www.missouribotanicalgarden.org.- “Thevetia peruviana.” PlantZAfrica. Accessed March 22, 2021. http://pza.sanbi.org.- “Yellow Oleander.” University of Florida. Accessed March 22, 2021. http://edis.ifas.ufl.edu.
