Origin
Grewia carpinifolia Juss. var. carpinifolia, also known as the White Crossberry or Crosseberry, is a plant species that belongs to the Tiliaceae family. It is native to Southeast Asia, specifically in Laos, Thailand, Vietnam, and the Philippines.
Common Names
The plant's common names vary depending on the region it is found. In Thailand, it is called "Ma-Nao-Thu-Khao" and in Laos, it is known as "Hang Ran."
Uses
The plant has useful properties in traditional medicine. Its roots and bark have been used as a remedy for diarrhea, stomach pains, and coughs. The plant also serves as a source of food for both humans and animals. Its ripe fruits are edible and often used to make jams or eaten fresh. The leaves and bark of the plant are also used to create blue and black dyes.
General Appearance
The White Crossberry plant is a small tree or shrub that grows up to 8 meters tall. It has an upright and spreading growth habit, with densely branched stems. The leaves are oval-shaped, dark green in color, and have serrated edges. The plant produces small, white or yellow flowers with five petals that bloom from May to August. The fruits are small, round, and turn from green to purple when ripe, with a sour taste and a texture similar to that of grapes.
Light Requirements
Grewia carpinifolia Juss. var. carpinifolia grows best in partial to full sunlight. It requires a minimum of four hours of direct sunlight each day to produce flowers. It can also tolerate partial shade, but prolonged periods of shade can negatively impact growth and flowering.
Temperature Requirements
The plant can grow in a wide range of temperatures but prefers warm to hot climates with an average temperature of 20 to 30 degrees Celsius. It can tolerate temperatures as low as 5 degrees Celsius but cannot survive frost.
Soil Requirements
Grewia carpinifolia Juss. var. carpinifolia thrives in well-draining sandy loam soil with a slightly acidic to neutral pH. It can also tolerate alkaline soils up to a pH of 8. It cannot tolerate waterlogged soil and requires regular watering during the growing season. In addition, like most plants, it benefits from regular fertilization.
Cultivation
Grewia carpinifolia Juss. var. carpinifolia, commonly known as the crossberry, is a shrub that grows in well-drained soils or rocky terrain. It prefers a location with full sun or partial shade. Planting should be done during springtime, in a hole that is twice the size of the plant's root ball. The hole should be filled with soil, and the plant should be watered thoroughly.
Watering Needs
Grewia carpinifolia Juss. var. carpinifolia requires regular watering during the first year of growth. After that, it can sustain itself in most weather conditions without needing supplemental watering. It is essential to ensure that the soil is well-drained and not waterlogged, as this can lead to root rot, which can damage or kill the plant.
Fertilization
During the growing season, Grewia carpinifolia Juss. var. carpinifolia benefits from regular fertilization, which is usually applied once every month. A balanced, slow-release fertilizer is recommended, as it will provide the necessary nutrients for the plant to grow healthy and strong. Fertilization should be done during spring, and additional supplements can be used during the remainder of the growing season.
Pruning
Grewia carpinifolia Juss. var. carpinifolia typically needs little pruning; however, it can be done to remove dead or diseased branches, and to shape the plant to the desired size and shape. Pruning should be done during the winter months, when the plant is dormant. As a general rule, no more than a third of the plant should be removed during a single pruning session, as too much pruning can damage the plant and reduce its overall health.
Propagation of Grewia carpinifolia Juss. var. carpinifolia
Grewia carpinifolia Juss. var. carpinifolia can be propagated through seeds or vegetative methods such as stem cuttings and layering.
Propagation by Seeds
Seeds of Grewia carpinifolia Juss. var. carpinifolia can be collected from the matured fruits. The collected seeds must be soaked in water for 24 hours before sowing in seed trays. The seed trays should be filled with well-draining soil and placed in a shaded area. The seeds will germinate within 2-4 weeks.
Propagation by Stem Cuttings
Stem cuttings can be taken from a healthy and disease-free plant during the growing season. The cuttings should be 6-8 inches long with 2-3 leaves. The lower leaves should be removed, and the cuttings should be dipped in rooting hormone powder. The cuttings should be planted in a well-draining soil mix, kept moist, and placed in a shaded area. Rooting will take place within 4-6 weeks.
Propagation by Layering
Grewia carpinifolia Juss. var. carpinifolia can also be propagated through layering. A healthy and disease-free branch should be selected and a portion of the bark should be removed where the branch touches the soil. The bark should be covered with moist soil and secured in place with a U-shaped wire. The layered branch should be kept moist and well-nourished until roots grow from the wounded area. The new plant can be separated from the mother plant and replanted in a new location.
Disease and Pest Management for Grewia carpinifolia Juss. var. carpinifolia
Grewia carpinifolia Juss. var. carpinifolia is a resilient plant that can resist pests and diseases quite effectively. However, in some cases, this plant may suffer from several pest attacks and diseases. Here are some common diseases and pests that might affect the plant and suggest ways to manage them.
Pests
1. Mealybug: Mealybugs can be a persistent problem for Grewia carpinifolia. They suck the sap of the plant, leading to yellowing and stunted growth. To manage mealybugs, you can spray water or insecticidal soap onto the plant to dislodge them. You can also introduce natural enemies like parasitic wasps, ladybugs, or lacewings to control the population.
2. Spider Mites: Spider mites are tiny pests that suck the sap of the plant, causing yellow spots and dropping of leaves. To manage spider mites, you can spray the leaves with water to dislodge them or introduce predatory mites like Phytoseiulus persimilis, which can eat spider mites.
3. Caterpillars: Caterpillars can feed on the foliage of the plant, leading to defoliation. To manage caterpillars, you can handpick them or use Bacillus thuringiensis (Bt) sprayed on the plant, which is poisonous to caterpillars.
Diseases
1. Leaf Spot: Leaf spot is a fungal disease that causes brown spots on the leaves. To manage this disease, you can spray the plant with a copper-based fungicide or remove the affected leaves and burn them. You can also improve the airflow around the plant to reduce humidity and prevent the spread of the disease.
2. Powdery Mildew: Powdery mildew is a fungal disease that causes white, powdery patches on the leaves and stems. To manage this disease, you can spray the plant with a fungicide that contains potassium bicarbonate or neem oil. You can also remove the affected leaves and improve the airflow around the plant.
3. Anthracnose: Anthracnose is a fungal disease that causes brown spots on the leaves and fruits of the plant. To manage this disease, you can spray the plant with a copper-based fungicide or remove the affected leaves and fruits. You can also improve the airflow around the plant to reduce humidity and prevent the spread of the disease.
Regular inspection of the plant and proper sanitation practices can help prevent pests and diseases from affecting Grewia carpinifolia. A healthy plant is less susceptible to pest attacks and diseases. Proper watering, fertilization, and pruning practices can go a long way in maintaining the health and vigor of the plant.
