Cestrum

Description

Cestrum is a genus of flowering plants that belongs to the nightshade family, Solanaceae. It comprises around 150 species of evergreen shrubs, trees, and vines that are native to the tropical and subtropical regions of the Americas. The plants produce small, tubular flowers that are usually greenish-yellow, white, or purple, and are highly fragrant. Some Cestrum species are cultivated as ornamental plants for their attractive foliage and flowers, while others have medicinal properties.

Taxonomic Information

Appearance

Cestrum plants have simple, alternate leaves that are usually lance-shaped or elliptical, and can be up to 30 cm long. The leaves are dark green and glossy, and some species have serrated or wavy margins. The flowers of Cestrum are borne in clusters or panicles, and are usually tubular in shape. They have five petals that are fused at the base, and a long, slender tube that extends beyond the petals. The flowers are highly fragrant and attract pollinators such as moths and butterflies. The fruits of Cestrum are small, berry-like capsules that contain numerous seeds.

Care Guide

Cestrum plants are generally easy to care for and can tolerate a wide range of growing conditions. Here are some tips for caring for Cestrum:

• Water: Water Cestrum plants regularly, but make sure the soil is well-drained to prevent waterlogging. Avoid over-watering, as this can cause root rot.
• Fertilization: Fertilize Cestrum plants once a month during the growing season with a balanced, all-purpose fertilizer.
• Soil: Cestrum plants prefer well-drained soil that is rich in organic matter. They can tolerate slightly acidic to slightly alkaline soil.
• Sunlight: Cestrum plants prefer full sun to partial shade. They can tolerate some shade, but may produce fewer flowers.
• Hardiness Zones: Cestrum plants are hardy in USDA zones 8 to 11. They can be grown as annuals in colder climates.

Common Pests & Diseases

Cestrum plants are generally resistant to pests and diseases, but they may occasionally be affected by the following:

• Spider mites: These tiny insects can cause webbing on the leaves and suck the sap from the plant. Use insecticidal soap or neem oil to control them.
• Whiteflies: These small, white insects can cause yellowing and wilting of the leaves. Use insecticidal soap or neem oil to control them.
• Leaf spot: This fungal disease causes brown spots on the leaves. Remove affected leaves and use a fungicide to prevent the spread of the disease.

Habitat

Cestrum plants are native to the tropical and subtropical regions of the Americas, including Mexico, Central America, and South America. They are found in a variety of habitats, including forests, thickets, and open areas. Some species of Cestrum have become naturalized in other parts of the world, including Australia, Africa, and Asia.

Question and Answer

Q: Can Cestrum plants be grown in containers?
A: Yes, Cestrum plants can be grown in containers as long as they have well-drained soil and are watered regularly.

Q: Are Cestrum plants toxic?
A: Yes, some species of Cestrum are toxic and can cause skin irritation and gastrointestinal problems if ingested.

Q: Do Cestrum plants attract pollinators?
A: Yes, Cestrum plants are highly fragrant and attract pollinators such as moths and butterflies.

Q: How often should I fertilize my Cestrum plant?
A: Fertilize Cestrum plants once a month during the growing season with a balanced, all-purpose fertilizer.

Related Plants

• Nicotiana
• Petunia
• Solanum

References

• Bailey, L. H., & Bailey, E. Z. (1976). Hortus third: A concise dictionary of plants cultivated in the United States and Canada. Macmillan.
• Govaerts, R., Sobral, M., Ashton, P., Barrie, F., Holst, B. K., Landrum, L. L., … & Wilson, K. L. (2018). World checklist of Solanaceae. Royal Botanic Gardens, Kew.
• Huxley, A. (1992). The new RHS dictionary of gardening. Macmillan.