Origin and Common Names
Justicia mossambicensis (Klotzsch) Lindau is a species of flowering plant in the family Acanthaceae. It is native to eastern and southern Africa and is commonly known as the red justicia, Mozambique justicia, or blood justicia.
Appearance
Justicia mossambicensis is a perennial herb that grows up to 90cm tall. It has hairy stems and leaves that are oblong and pointed, measuring up to 10cm in length. The plant produces small, showy, dark red flowers that bloom from summer to fall. The flowers are borne in terminal clusters and have conspicuous dark purple bracts. The fruit is a capsule containing numerous small, black seeds.
Uses
Justicia mossambicensis is primarily grown as an ornamental plant for its attractive flowers and foliage. It can be used in tropical gardens and is suitable for growing in containers. The crushed leaves are sometimes used in traditional medicine to treat skin rashes, wounds, and fever. In some parts of Africa, the plant is used to make a red dye that is used to colour cloth and leather.
Growth Conditions for Justicia mossambicensis
Justicia mossambicensis (Klotzsch) Lindau is a tropical plant that requires specific growth conditions to thrive.
Light Requirements
The plant requires a significant amount of light to support its growth. Growers should provide it with about 6-8 hours of bright, direct light per day. However, exposure to too much direct sunlight can cause damage to the leaves. As such, it is recommended to place the plant in partial shade during the hottest hours of the day.
Temperature Requirements
Justicia mossambicensis thrives in warm temperatures ranging from 60-77 degrees Fahrenheit (15-25 degrees Celsius). The plant does not tolerate frost well and should be protected from extreme cold weather. Ideal temperatures for the plant are above 50 degrees Fahrenheit (10 degrees Celsius).
Soil Requirements
The plant requires well-draining soil that retains enough moisture for proper growth. The ideal pH range for the soil should be between 6.0 and 7.0. To ensure optimum growth, growers can mix the soil with compost or peat moss. This will enrich the soil with nitrogen and other essential nutrients needed for plant growth.
Cultivation
Justicia mossambicensis is a tropical plant that thrives in warm, humid conditions. It can be grown both indoors and outdoors, but it requires a warm climate, with temperatures above 60°F (15°C) and plenty of sunlight.
The plant prefers well-drained soil that is rich in organic matter, and it should be planted in a location that is protected from strong winds. Justicia mossambicensis can be propagated through cuttings or seeds, and it should be planted in the spring or summer.
Watering
Justicia mossambicensis requires regular watering to keep the soil moist but not waterlogged. Water the plant deeply once a week, or more often if the top inch of soil feels dry to the touch. During hot and dry periods, the plant may require more frequent watering.
Avoid getting water on the leaves and flowers, as this can cause fungal diseases to develop. Water the plant at the base, and use a watering can or hose with a gentle stream to avoid damaging the plant.
Fertilization
Justicia mossambicensis benefits from regular fertilization, which promotes healthy growth and blooming. Use a balanced, water-soluble fertilizer every two weeks during the growing season (spring and summer). Follow the instructions on the fertilizer package and avoid over-fertilizing, as this can damage the plant.
Pruning
Justicia mossambicensis benefits from pruning, which promotes bushy growth and helps the plant maintain its shape and size. Prune the plant in the early spring before new growth begins, cutting back any dead or damaged branches and thinning out crowded areas.
You can also prune the plant after blooming to encourage a second round of flowers. Cut back the stems by about one-third, making the cut just above a leaf joint or node.
Propagation of Justicia mossambicensis
There are several methods of propagating Justicia mossambicensis, which include:
Seed Propagation
Seeds of Justicia mossambicensis are very small and numerous. They can be sown in seed trays containing a well-drained soil mix. Cover only slightly with a layer of peat moss or vermiculite. Keep moist and place in warm, well-lit areas. Germination usually occurs within 1 to 2 weeks. Once the seedlings are big enough to handle, they can be transplanted into individual pots.
Cutting Propagation
Cuttings can be taken during the growing season, usually from June to August. Take softwood cuttings, around 10 cm long, from the tips of healthy stems. Dip the cuttings into rooting hormone and place them in a potting mix made up of peat moss and sand. Keep the cuttings moist and place in a shaded area. Within 3 to 4 weeks, roots should start to form.
Division Propagation
This method of propagation usually happens during the plant's natural repotting process. Divide the plant by gently teasing the roots apart during repotting, ensuring that each section contains a portion of the stem with leaves. Plant each division in new pots filled with a well-drained soil mix, and keep moist. Place the pots in a shaded area until new growth appears, usually within a few weeks.
Disease Management
Justicia mossambicensis is fairly resistant to diseases but may be susceptible to root rot, leaf spot, and powdery mildew infections.
Root Rot
Root rot is a fungal disease that thrives in wet soil conditions. It causes stunted growth, wilting, and yellowing of the leaves. To manage root rot, ensure the plant is not overwatered, and the soil is well-draining. Improve the soil drainage by adding organic matter and avoid planting in compacted soils. Fungicide application may also be necessary if the condition persists.
Leaf Spot
Leaf spot is also a fungal disease characterized by brown spots on the leaves. The spots may merge, leading to defoliation and weakening of the plant. Manage this disease by maintaining good air circulation around the plant, removing infected leaves, and applying a copper fungicide spray.
Powdery Mildew
Powdery mildew is a fungal disease that affects the leaves, leading to white or gray powdery patches. It causes stunted growth and may lead to leaf drop. To manage powdery mildew, avoid overhead watering, maintain good air circulation, and remove any infected leaves. Neem oil or a sulfur fungicide can also be effective in managing the disease.
Pest Management
Justicia mossambicensis is not usually affected by pests, but it may be attacked by spider mites, aphids, and mealybugs.
Spider Mites
Spider mites are tiny pests that feed on plant sap, leading to discoloration of the leaves and stunted growth. They tend to thrive in hot and dry conditions. To manage spider mites, spray the plant with a strong jet of water, maintain high humidity levels, and apply insecticidal soap or neem oil.
Aphids
Aphids are small insects that suck the sap of the plant, leading to twisted leaves and stunted growth. To manage aphids, spray the plant with a strong jet of water or apply insecticidal soap. Alternatively, introduce natural predators such as ladybugs, lacewings, or parasitic wasps.
Mealybugs
Mealybugs are small, white, cottony pests that also feed on plant sap, leading to yellowing and weakened growth. They tend to hide in leaf axils and crevices. To manage mealybugs, use a cotton swab dipped in alcohol to kill the pests, or spray the plant with insecticidal soap. Alternatively, introduce natural predators such as ladybugs, lacewings, or parasitic wasps.
