Origin
Justicia flava (Vahl) Vahl, also known as yellow justicia, is a wild plant that is commonly found in the tropical regions of Africa, especially in the west and east parts of the continent. It is also found in other parts of the world, including Asia and America.
Common Names
The plant is commonly known by various names, including yellow justicia, yellow shrimp plant, golden shrimp plant, and yellow king's crown. These names are based on the plant's striking yellow flowers that resemble shrimps and its golden bracts that create a crown-like appearance.
Uses
Justicia flava has various medicinal and horticultural uses. The plant is known for its antibacterial and antifungal properties and is used to treat various illnesses such as respiratory tract infections and malaria. It is also used as a diuretic and a blood purifier. In horticulture, the plant is grown as an ornamental for its vibrant yellow flowers and attractive foliage. It is suitable for both indoor and outdoor landscaping and is easy to care for.
General Appearance
Justicia flava is a shrubby plant that grows up to 1.5 meters tall and wide. The plant has broad and glossy leaves that are dark green in color and oval-shaped. The leaves are arranged oppositely on the stem. The plant blooms with yellow flowers that are arranged in clusters and resemble shrimps. The flowers are surrounded by golden bracts that create a crown-like appearance. The plant blooms throughout the year and requires minimum care.
Light Requirements
Justicia flava (Vahl) Vahl grows best in bright, indirect sunlight. It can also thrive in partial shade but avoids direct sunlight. The plant can tolerate low light conditions, but too little light can result in slow growth and reduced flowering. Therefore, it is best to place the plant near a north-facing window or in an area where it can receive at least six hours of bright, indirect sunlight.
Temperature Requirements
Justicia flava (Vahl) Vahl prefers warm temperatures ranging from 21°C to 27°C. It can survive in cooler temperatures as low as 10°C, but growth may slow down. It is best to protect the plant from sudden temperature fluctuations, which can damage the leaves and flowers. Therefore, it is essential to keep the plant away from drafty areas such as near open windows and doors, and air conditioning vents.
Soil Requirements
Justicia flava (Vahl) Vahl grows well in well-draining soil that is rich in organic matter. The soil should be slightly acidic to neutral, ideally with a pH range between 6.0 and 7.0. The plant prefers a soil mixture consisting of equal parts of peat moss, perlite, and vermiculite. Additionally, the soil should be kept moist but not waterlogged, often requiring watering once a week. Always ensure that the soil is well-draining to avoid root rot.
Cultivation Methods
Justicia flava (Vahl) Vahl grows best in well-draining, moderately fertile, and slightly acidic soil. It is ideal to cultivate this plant in a location that receives ample sunlight with some shade. The seeds of this plant can be germinated indoors in small, moist pots before transferring them to their intended outdoor locations. It is recommended to plant them in spring or early summer when the temperatures are warm.
Watering Needs
Justicia flava (Vahl) Vahl thrives in consistently moist soil. Watering should be done regularly, but it is crucial to avoid overwatering to prevent root rot and waterlogging. It is best to water this plant only when the soil's top layer feels dry to the touch, and the water should penetrate deep into the soil to reach the roots.
Fertilization
Justicia flava (Vahl) Vahl responds well to regular fertilization. Organic fertilizers that are high in potassium and phosphorus can be applied to the soil. It is recommended to fertilize the plant during the growing season, which is spring and summer. Over-fertilization should be avoided as it can lead to the burning of the plant's roots.
Pruning
Justicia flava (Vahl) Vahl should be pruned regularly to maintain its shape. Dead leaves and branches should be removed as soon as possible to prevent disease and insect infestation. This plant can be pinched back to encourage bushier growth and more abundant blooming. Pruning should be done during the dormant season in fall or early spring, and it is best to sterilize pruning tools to disinfect them before use.
Propagation of Justicia flava
Justicia flava (Vahl) Vahl, commonly known as yellow shrimp plant, is propagated through various methods such as seeds, stem cuttings, and layering.
Propagation through seeds
The yellow shrimp plant produces small seeds that are viable for up to six months. To propagate the plant through seeds, select healthy matured seeds, and sow them in well-draining soil. Cover the seeds with a thin layer of soil and water gently. The seeds will germinate within two to four weeks.
Propagation through stem cuttings
Propagating the Justicia flava plant through stem cuttings is a practical method as it quickly produces new plants with similar characteristics as the parent plant. Select healthy semi-hardwood stem cuttings that are about 5 to 6 inches long, and remove the lower leaves. Dip the cut end in rooting hormone powder and plant it in well-draining soil. Keep the soil moist and warm, and the roots will develop within four to six weeks.
Propagation through layering
Layering involves bending a low hanging stem of the Justicia flava plant and covering a portion of it with soil while leaving the tip exposed. Apply rooting hormone powder to the covered section and keep it moist. After two to three months, new roots will begin to form, and the new plant can be separated from the parent plant and transplanted into another pot or garden bed.
Disease and Pest Management for Justicia flava
Justicia flava is a hardy plant that usually grows without major issues. However, there are disease and pest problems that can affect its growth and appearance. Here are some common diseases and pests that might affect the plant and ways to manage them:
Diseases
Leaf Spot: Leaf spot is caused by the fungus Cercospora and appears as circular gray, tan, or brown spots on the leaves. To manage this disease, remove infected leaves and destroy them to prevent the spread of the fungus. Make sure to water the plant at the base rather than from the top to prevent the leaves from getting wet. In severe cases, apply a fungicide according to the package instructions.
Root Rot: Root rot is caused by overwatering and poor drainage. To prevent this disease, make sure to plant the Justicia flava in well-draining soil and avoid overwatering. If root rot does occur, remove infected roots and adjust the watering schedule to prevent the soil from becoming too damp.
Pests
Whiteflies: Whiteflies are tiny insects that feed on the sap of the plant and cause the leaves to wither and turn yellow. To manage this pest, spray the plant with insecticidal soap or neem oil every seven to 14 days until the infestation is under control. You can also introduce natural predators like ladybugs or lacewings to control whitefly populations.
Spider Mites: Spider mites are also sap-sucking insects that cause the leaves to yellow and eventually drop. To manage this pest, spray the plant with a strong stream of water to dislodge the mites. You can also apply an insecticidal soap or neem oil to kill the remaining mites.
By following these disease and pest management tips, you can help ensure the Justicia flava grows healthy and strong. Remember to always monitor the plant and address any issues promptly to prevent further damage.
