General Overview
Erythrina sandwicensis O. Deg. var. luteosperma St. John, commonly known as the wiliwili, is a deciduous tree that is native to Hawaii. It is a member of the Fabaceae family, which is the third largest family of flowering plants worldwide. The wiliwili can grow up to 15 meters (50 feet) in height and 45 centimeters (18 inches) in diameter. It has a striking appearance due to its bright orange-red flowers and distinctive trunk shape, which can sometimes feature hollowed-out sections.
Appearance
The wiliwili has a unique appearance that sets it apart from other trees in the Hawaiian ecosystem. Its trunk can have a gnarled, twisted appearance, and may feature large hollow cavities. The tree's leaves are thin and elongated, and typically measure 10-20 centimeters (4-8 inches) in length. One of the most impressive features of the wiliwili is its bright orange-red flowers, which bloom in the spring and summer. These flowers are arranged in clusters and can measure up to 10 centimeters (4 inches) in diameter. The wiliwili's fruit is a woody pod that contains seeds with a distinctive bright yellow color.
Common Names and Uses
The wiliwili is known by several common names, including the Hawaiian name wiliwili, which means "repeatedly twisted" or "twisted again and again." The tree is culturally significant in Hawaii, and its wood has traditionally been used to create canoes, surfboards, and other tools and implements. The wiliwili's fruit was also used by native Hawaiians as a food source.
Today, the wiliwili is primarily grown as an ornamental tree, and can be found in many public parks and gardens. The tree is very drought-tolerant and can withstand harsh growing conditions, making it an attractive choice for landscaping in arid regions.
Light Requirements
Erythrina sandwicensis var. luteosperma grows best in areas with full sun exposure. It is recommended to provide the plant with at least six hours of direct sunlight daily for optimal growth. Insufficient sunlight may lead to stunted growth or decreased flowering.
Temperature Requirements
This plant grows best in warm temperatures, with a range of 60-85°F (15-29°C). It can tolerate occasional drops in temperature, but exposure to frost should be avoided as it may kill the plant. The typical temperature range found in tropical or subtropical areas is suitable for this plant to thrive.
Soil Requirements
Erythrina sandwicensis var. luteosperma grows in well-draining soil with a slightly acidic pH level between 5.5-6.5. The soil should be rich in organic matter and have a good mixture of sand, silt, and clay. Adding compost, peat moss, or other organic matter can help improve the soil's fertility and drainage. This plant is also sensitive to salt, so the soil should have minimal salt content to avoid damaging the roots.
Watering Requirements
Erythrina sandwicensis var. luteosperma requires regular watering, especially during the growing season. The plant should be watered once or twice a week, depending on the weather conditions and soil moisture level. It is important not to overwater or underwater the plant, as either condition can affect its growth and health. During the winter season, the watering frequency can be reduced to once or twice a month.
Cultivation Methods
Erythrina sandwicensis O. Deg. var. luteosperma St. John, commonly known as Hawaiian coral tree, is a tropical evergreen tree. The tree thrives in well-drained soils that are rich in organic matter. It can be planted in pots or in the ground, provided that the soil is moist and well-drained. The ideal planting site should receive partial shade, and the temperature should range from 60 to 85°F. During the first year of growth, young trees require regular watering and protection from direct sunlight.Watering Needs
Hawaiian coral tree requires moderate watering during the growing season. Watering frequency will depend on the climate and the soil of the planting site. The soil should be kept moist, but not waterlogged. Overwatering can cause root rot. During dry seasons, it is recommended to give the tree a deep watering at least once a week.Fertilization
To ensure optimal growth, fertilize Erythrina sandwicensis O. Deg. var. luteosperma St. John every three months during the growing season. Use a balanced fertilizer with an NPK ratio of 10-10-10. Apply the fertilizer at the tree's dripline and water thoroughly afterward.Pruning
Hawaiian coral tree requires minimal pruning. Pruning should be done during the dormant season to maintain the desired shape and size. To maintain a good branching structure, remove any weak, damaged, or crossing branches. To maintain the tree's size, prune back the tips of the branches after flowering to encourage new growth.Propagation of Erythrina sandwicensis O. Deg. var. luteosperma St. John
Erythrina sandwicensis O. Deg. var. luteosperma St. John, commonly known as the wiliwili tree, is a tropical species native to Hawaii. It is a popular ornamental plant due to its stunning display of red-orange flowers and unique cork-like trunk. Here are some methods for propagating wiliwili trees:
Seed Propagation
One of the most common ways to propagate wiliwili trees is through seed propagation. Seeds can be collected from mature fruit pods, which are usually found on the tree from March to September. Once collected, the seeds can be soaked in water for a few days to soften the hard outer seed coat, making it easier to germinate. After soaking, the seeds can be planted in soil or a seedling tray, and they should germinate within a few weeks. Seedlings should be transplanted once they are large enough to handle, or kept in the tray until they are ready to be planted in their permanent location.
Cuttings
Another method of propagation for wiliwili trees is through cuttings. Hardwood cuttings are taken from the tree during the dormant season, which is typically from November to January. Cuttings should be taken from branches that are at least one year old, and they should be about 6-8 inches long. Once cut, the bottom end of the cutting should be dipped in rooting hormone and planted in a well-draining soil mix. The cutting should be kept moist and out of direct sunlight until it begins to form roots, which usually takes several weeks to a few months.
Air Layering
Air layering is a more advanced method of propagation that can be used for wiliwili trees. This technique involves making a small cut in the bark of a mature branch, and then wrapping moist sphagnum moss around the cut area. The moss is then wrapped in plastic to hold in moisture and promote root growth. Once roots have formed, the branch can be cut from the parent tree and planted in a new location.
Propagation of Erythrina sandwicensis O. Deg. var. luteosperma St. John can be an enjoyable and rewarding process, leading to beautiful new trees that can be enjoyed for years to come.
Disease Management
Erythrina sandwicensis O. Deg. var. luteosperma St. John is susceptible to several diseases, including:
- Leaf spot: Caused by the fungus Cercospora, this disease is characterized by circular to irregularly shaped brown spots on the leaves. To manage it, remove and destroy infected plant parts, improve air circulation, and avoid overhead watering.
- Powdery mildew: This fungal disease appears as a white powdery coating on the leaves. To manage it, prune infected plant parts, improve air circulation, avoid overhead watering, and apply fungicides if necessary.
- Rust: Caused by the fungus Phakopsora erythrinae, rust appears as small orange to brown spots on the leaves. To manage it, remove and destroy infected plant parts and apply fungicides if necessary.
Pest Management
Erythrina sandwicensis O. Deg. var. luteosperma St. John is also prone to attack by several pests, including:
- Aphids: These small insects cluster on the undersides of leaves and suck plant sap, causing distortions and yellowing of leaves. To manage them, spray the plant with a strong stream of water, introduce natural predators like ladybugs, or use insecticidal soap.
- Spider mites: These tiny pests spin webs on the undersides of leaves and suck plant sap, causing yellowing and bronzing of leaves. To manage them, remove and destroy infected plant parts, improve humidity levels, and apply insecticides if necessary.
- Mealybugs: These small white insects congregate on leaves and stems and suck plant sap, causing yellowing and stunted growth. To manage them, wipe the plant with a cloth soaked in rubbing alcohol, introduce natural predators like ladybugs, or use insecticidal soap.
