Cestrum is a genus of flowering plants in the Solanaceae family, which includes around 170 species. These plants are primarily found in tropical and subtropical regions of the Americas, but some species are also found in parts of Asia and Africa. Cestrum plants are known for their fragrant flowers and are commonly grown for ornamental purposes in gardens.

Key Features of Cestrum:

1. Foliage:

   • The leaves of Cestrum plants are generally glossy, oval, and dark green in color. They may have a slightly rough texture and are arranged alternately along the stem.
   • Some species, like Cestrum nocturnum (night-blooming jasmine), are known for the strong fragrance of their leaves when crushed.

2. Flowers:

   • The flowers of Cestrum plants are tubular and often come in clusters. They are typically small but very aromatic.
   • Common colors include white, yellow, pink, and red, depending on the species.
   • Many Cestrum species are known for their night-blooming flowers, which release a strong, sweet fragrance in the evening.

3. Fruit:

   • Cestrum plants produce small, berry-like fruits that contain seeds. The fruit is generally not the main ornamental feature of the plant but can contribute to the plant's overall appearance.

Growing Conditions:

1. Light:

   • Cestrum plants prefer full sun or partial shade. In bright, direct sunlight, the plants grow best and produce more flowers. However, they can tolerate some light shade, particularly in very hot climates.

2. Watering:

   • Cestrum prefers consistently moist, well-draining soil but should not be waterlogged. Water the plant regularly, but make sure the soil dries out slightly between waterings to prevent root rot.
   • During dry periods, ensure the plant is watered more frequently.

3. Soil:

   • It grows best in fertile, well-draining soil. It can tolerate a range of soil types but prefers slightly acidic to neutral pH (6.0–7.0).
   • If planting in a container, use a good-quality potting mix with added organic matter to ensure proper drainage.

4. Temperature:

   • Cestrum is a warm-climate plant and thrives in tropical and subtropical environments. It is frost-sensitive and should be protected from freezing temperatures.
   • It is best suited for USDA Hardiness Zones 9–11, though it can be grown as an annual in cooler climates or brought indoors during winter.

5. Humidity:

   • These plants prefer higher humidity levels but can tolerate average household humidity, especially in tropical or subtropical climates.

6. Fertilizing:

   • Cestrum benefits from regular feeding with a balanced, slow-release fertilizer during the growing season (spring and summer). A liquid fertilizer applied every few weeks can help promote healthy growth and flowering.
   • Reduce fertilization in the fall and winter when the plant's growth slows.