Origin
Justicia diclipteroides Lindau subsp. usambarica Hedrén, commonly known as Usambara shrimp plant, is an ornamental plant that belongs to the family of Acanthaceae. It is native to Tanzania, specifically in the East Usambara Mountains in northeastern Tanzania. The plant is endemic to this mountain range, and it is also found growing in the coastal forests of Kenya.
Common Names
Aside from its scientific name, Justicia diclipteroides Lindau subsp. usambarica is commonly known as Usambara shrimp plant, shrimp plant, or blue shrimp plant. The plant earned its name from its unique inflorescence that resembles a shrimp, especially when it is in its deep blue coloration.
Uses
Justicia diclipteroides Lindau subsp. usambarica is primarily used as an ornamental plant. Its deep blue coloration and shrimp-like flowers make it a popular choice for gardeners and horticulturists who want to add a unique touch of color to their outdoor spaces. The plant is also an excellent cut flower and can be used to make stunning flower arrangements.
General Appearance
The Usambara shrimp plant is a short-lived perennial shrub that grows up to 1.2 meters tall and wide. It has a dense and bushy habit, with multiple stems that emerge from the base of the plant. The leaves are lance-shaped, about 10 cm long and 2 cm wide, and are dark green in color. The flowers are produced in dense inflorescences, and they are deep blue with white-tinged bracts. The flowers can be up to 7.5 cm long and 5 cm wide, and they have a shrimp-like appearance, giving the plant its common name. The plant blooms heavily in the summer, attracting pollinators like bees, butterflies, and moths.
Light Requirements
Justicia diclipteroides Lindau subsp. usambarica Hedrén prefers bright, indirect sunlight or partial shade. Direct sunlight can scorch the leaves and cause the plant to wilt. In indoor settings, placing the plant near a west or south-facing window can offer the right amount of light without exposing it to direct sun rays.
Temperature Requirements
This plant thrives in warm temperatures between 70°F to 85°F (21°C to 29°C). In cooler temperatures, the plant growth may be stunted and the leaves may start to drop. The ideal night temperature should be between 60°F to 65°F (16°C to 18°C). Avoid placing the plant in cold drafts, as it may harm the plant.
Soil Requirements
Justicia diclipteroides Lindau subsp. usambarica Hedrén prefers well-draining soil with a pH range between 6.0 to 7.5. A mixture of organic and inorganic materials, such as peat moss, perlite, and vermiculite, can provide a suitable growing environment for the plant. Avoid using heavy soil, as it can retain too much moisture and lead to root rot.
Cultivation Methods
Justicia diclipteroides Lindau subsp. usambarica Hedrén is native to East Africa and can be grown both indoors and outdoors. It requires well-draining soil and partial shade to full sunlight. Outdoor plants do well in USDA hardiness zones 9 to 11.
Watering needs
This plant requires regular watering, particularly during the growing season. It is important to avoid overwatering, as this can lead to root rot. Water the plant when the soil is dry to the touch, and ensure proper drainage. Reduce watering during the colder months.
Fertilization
Justicia diclipteroides Lindau subsp. usambarica Hedrén benefits from regular fertilization during the growing season. Use a balanced fertilizer with equal parts nitrogen, phosphorus, and potassium. Apply the fertilizer every four weeks at half strength to avoid damaging the roots.
Pruning
Pruning is essential to maintaining the shape and size of Justicia diclipteroides Lindau subsp. usambarica Hedrén. Prune back leggy or overgrown stems to encourage bushier growth and remove any diseased or damaged leaves. Pruning should be done in the early spring or late fall.
Propagation of Justicia diclipteroides Lindau subsp. usambarica Hedrén
Justicia diclipteroides Lindau subsp. usambarica Hedrén is best propagated from seeds. The plant produces a large number of seeds that can be easily collected for propagation. The ideal time for collecting the seeds is when the seed capsules turn yellow or brown and start to split open.
The seeds can be sown immediately after harvesting in a well-draining seed starting mix. They should be lightly covered with soil and kept in a warm, humid location. The seedlings should emerge within 7-10 days.
Alternatively, the seeds can be stored in a cool and dry location, such as a refrigerator, for up to six months before sowing.
Propagation from cuttings is also possible, but it is less reliable than seed propagation. Cuttings should be taken from the plant's new growth in the spring or early summer and rooted in a well-draining potting mix. The cuttings should be kept in a warm, humid location and monitored closely to ensure they do not dry out.
Disease Management for Justicia diclipteroides Lindau subsp. usambarica Hedrén
Justicia diclipteroides Lindau subsp. usambarica Hedrén, commonly known as Usambara Justicia, is a relatively hardy plant with no major disease problems. However, it is still susceptible to some diseases that could affect its growth and productivity. Here are some of the common diseases that could affect this plant:
Fungal Diseases
Fungal diseases are the most common diseases that affect plants, and Justicia diclipteroides Lindau subsp. usambarica Hedrén is no exception. This plant can be affected by foliar diseases such as powdery mildew, leaf spot, and rust. Powdery mildew is a grayish powdery growth that appears on the leaves, while leaf spots appear as small, circular, dark spots on the leaves. Rust appears as yellow or orange pustules on the leaves.
To manage these fungal diseases, it is essential to keep the plant's foliage dry by avoiding overhead watering. Remove any infected leaves or plant parts and dispose of them to prevent the disease from spreading. Use fungicides as a last resort when the disease has become severe.
Bacterial Diseases
Justicia diclipteroides Lindau subsp. usambarica Hedrén can also be affected by bacterial diseases such as bacterial leaf spot and bacterial wilt. Bacterial leaf spot appears as small, water-soaked spots on the leaves that enlarge and turn dark with time. Bacterial wilt causes the plant to wilt suddenly and die.
To manage bacterial diseases, it is important to practice good sanitation by removing infected plant parts and disposing of them. Avoid overhead watering, as this can spread bacteria. Use a copper-based fungicide to manage bacterial leaf spot, and use resistant cultivars to manage bacterial wilt.
Pest Management for Justicia diclipteroides Lindau subsp. usambarica Hedrén
Justicia diclipteroides Lindau subsp. usambarica Hedrén is also susceptible to attack by pests that could affect its growth and productivity. Here are some of the common pests that could affect this plant:
Mites
Spider mites can cause significant damage to the leaves of Justicia diclipteroides Lindau subsp. usambarica Hedrén. These mites suck sap from the leaves, causing them to become yellow, dry, and ultimately die.
To manage spider mites, ensure that the plant is well-watered and kept in a humid environment. Wipe the leaves with a damp cloth regularly to prevent the mites' buildup. Use a miticide if the infestation is severe.
Mealybugs
Mealybugs are small, white, cotton-like insects that suck sap from the plant, causing stunted growth and leaf drop. They also produce a sticky substance called honeydew, which can attract ants and other insects.
To manage mealybugs, use a cotton swab dipped in rubbing alcohol to kill them. Use insecticidal soap or a neem-based product if the infestation is severe.
Regular monitoring of the plant and good cultural practices such as proper watering and fertilization can help prevent the occurrence and spread of diseases and pests on Justicia diclipteroides Lindau subsp. usambarica Hedrén.
