Origin and Common Names
Melicope hosakae, also known as Ohi'a, is a flowering tree native to Hawaii, specifically the islands of Maui, Molokai, and East Maui. It belongs to the Rutaceae family and is a close relative of the citrus tree. The plant is widely known by its common name Ohi'a, referring to the tree's broad, deeply-veined leaves, and its fragrant, white flowers.Appearance
Melicope hosakae typically grows as a small tree, reaching heights of up to 15 feet. It has smooth, brownish-grey bark and glossy, dark green leaves that alternate along the branches. The leaves are ovate-oblong in shape, with a length of up to 10 inches. The tree produces clusters of fragrant, white flowers that bloom throughout the year, eventually giving way to small, round, reddish-brown fruit.Uses
Ohi'a has a long history of traditional use in Hawaiian culture. The leaves and bark of the tree were used to treat a variety of ailments, including diarrhea, fever, and stomach problems. The fragrant flowers were similarly used to relieve headache and lightheadedness. In modern times, the plant is primarily used in landscaping and ornamental horticulture, prized for its attractive foliage and striking flowers. Despite its many medicinal uses, Ohi'a should be consumed with caution, as some parts of the plant are toxic if ingested.Light Requirements
The Melicope hosakae plant grows best in full sun, but it can also tolerate a partially shady location. It needs a minimum of six hours of direct sunlight every day. Lack of adequate sunlight can result in stunted growth, poor flowering, and weak stems.
Temperature Requirements
The plant requires average to warm temperatures to grow and thrive. The optimum temperature range is between 20°C to 30°C (68°F to 86°F). Temperatures below 10°C (50°F) can lead to root damage, while a temperature above 35°C (95°F) can cause flower buds and leaves to drop. High humidity is also essential for healthy growth.
Soil Requirements
Melicope hosakae requires well-drained soil with a slightly acidic to neutral pH range of 6.0 to 7.5. The plant is ideal for sandy and loamy soils. The soil should also be rich in nutrients and organic matter to promote healthy root development. Soil that is too dry or too wet can lead to root rot and other fungal diseases. It is essential to ensure that the soil is moist but not waterlogged.
Cultivation
Melicope hosakae is perennial shrub widely cultivated for ornamental purposes. It is a low-growing plant that can grow up to three feet tall. The plant grows best in well-drained, slightly acidic soil with a pH range of 6.0 to 6.5. It prefers partial shade to full sun conditions.
The plant can be propagated by stem and tip cuttings, bud grafting, and seedlings. Tip cuttings should be taken in the spring and summer months and kept in a warm and humid environment to promote root growth.
Watering Needs
Melicope hosakae requires moderate watering habits in well-draining soil. Keep the soil moist, but not waterlogged or saturated, as it can lead to root rot. Allow the soil to dry slightly between the watering intervals.
Fertilization
The plant requires regular fertilization to promote healthy growth. Fertilize the plant every two to three weeks during the growing season with a slow-release fertilizer.
Avoid over-fertilization as it can lead to excessive vegetative growth and reduced flowering. Stop fertilizing during the winter months as the plant goes through a dormant phase.
Pruning
Regular pruning promotes a bushy and compact plant structure that enhances its ornamental value. The plant can be pruned in the spring and fall months, removing any dead or diseased leaves and branches.
Remove any branches that cross or rub against each other. Prune back the tips of the stems to promote branching and encourage new growth. Avoid over-pruning or cutting back the plant too much as it can lead to reduced flowering and growth.
Propagation of Melicope hosakae (St. John) W.L. Wagner & R.K. Shannon
Melicope hosakae (St. John) W.L. Wagner & R.K. Shannon, commonly known as alani, is a native Hawaiian plant species that belongs to the Rutaceae family. It can be propagated either by seeds or vegetatively.
Propagation by seeds
Propagation by seeds is the primary method used to propagate Melicope hosakae, especially for large-scale propagation. The following steps outline the process:
1. Collect mature healthy seeds from the parent plant during the fall season.
2. Clean the seeds carefully to remove any debris or impurities. This will help reduce the possibility of fungal and bacterial infections.
3. Germinate the seeds in a clean, well-drained potting mix, preferably one that is rich in organic matter. Cover the seeds lightly with soil and keep them moist throughout the germination process.
4. Provide consistent moisture, warmth, and bright light to the seeds. Ensure that the temperature remains between 25-30°C in a warm place, preferably a greenhouse.
5. Keep monitoring the seeds until they germinate, which can take up to 6 weeks.
Propagation by vegetative methods
Melicope hosakae can also be propagated vegetatively through stem cuttings, layering, and grafting. Here are the various ways of vegetative propagation:
1. Stem cuttings: Take cuttings from a healthy mature plant, preferably in the spring or early summer season. The cutting tip should have two leaves and a terminal bud. Strip away the bottom leaves, leaving only the top two or three. Dip the stem in rooting hormone, then insert it into a well-drained potting mix. Keep the cutting moist and in a warm and bright environment until roots appear.
2. Layering: This method involves bending a low branch to the ground and covering a portion of it with soil. The covered portion will develop roots while still attached to the parent plant. Once roots have developed, sever the new plant from the parent and transplant it to a larger pot or garden bed.
3. Grafting: Grafting is a more advanced method of propagation and requires some expertise. It involves joining a scion (a stem from a desired cultivar) to a rootstock (a stem from an established plant). After joining the two pieces, they are held together until they grow together.
With proper care, propagation of Melicope hosakae can be successful with both vegetative and seed propagation techniques.
Disease and Pest Management for Melicope hosakae
Melicope hosakae is a relatively easy plant to grow, but it can still be vulnerable to diseases and pests. Here are some common issues and ways to manage them:
Diseases
Anthracnose: This fungal disease can cause leaf spots that eventually merge and cause defoliation. It can be managed by pruning affected leaves, removing leaf debris, and applying a fungicide.
Cercospora Leaf spot: This disease causes brownish-gray spots on leaves, which can lead to premature leaf drop. It can be prevented by avoiding overhead watering and applying a copper fungicide.
Root Rot: Overwatering can cause root rot in Melicope hosakae. To prevent this, make sure the soil is well-draining and avoid overwatering. If root rot has already occurred, it may be necessary to repot the plant in fresh, well-draining soil.
Pests
Aphids: These small, soft-bodied insects can feed on the plant's sap and cause yellowed, curled leaves. They can be controlled by using insecticidal soap or neem oil.
Spider Mites: These tiny pests can cause leaves to yellow and drop off. The use of a miticide is necessary in managing spider mites.
Mealybugs: These insects leave a white, waxy residue on the leaves and stems and can cause stunted growth. They can be managed by using insecticidal soap or neem oil.
Regular monitoring of the plant for any changes in its growth, appearance, or discoloration can help identify issues and allow for prompt treatment of pests and diseases. Proper care and maintenance can prevent or minimize problems, helping to ensure that this plant remains healthy and thriving.
