Overview
Pittosporum napaliense Sherff is a species of flowering plant in the family Pittosporaceae. The plant is native to the Hawaiian Islands in the United States.
Common Names
Pittosporum napaliense Sherff is commonly known as the N?pali Coast Cheesewood or Kaulu.
Uses
The N?pali Coast Cheesewood is commonly used in landscaping due to its attractive appearance. It is also used in traditional Hawaiian medicine as a treatment for stomach and intestinal problems.
Appearance
Pittosporum napaliense Sherff is a small to medium-sized tree that can grow up to 25 feet tall. Its leaves are dark green and glossy, and it produces small, white to cream-colored flowers that have a sweet fragrance. The tree produces fruit that is a woody capsule that contains seeds.
Light Requirements
Pittosporum napaliense Sherff prefers partially shaded conditions, making it an ideal plant for understory planting or growing under the shade of larger trees. This plant can also tolerate full sun exposure, but it may require additional irrigation in hotter climates.
Temperature Requirements
This plant prefers warm temperatures and is hardy to USDA Zones 9a-11. It can tolerate temperatures as low as 20°F (-6°C) for brief periods, but it is not recommended for areas with extended frosts or freezes. In areas with extreme heat, semi-shaded conditions may be necessary to prevent leaf scorching.
Soil Requirements
Pittosporum napaliense Sherff prefers well-draining soils that are rich in organic matter. It can grow in a range of soil types, including loamy, sandy, or clay soils. This plant prefers soils with a pH between 5.0 to 7.5. Prior to planting, it is recommended to amend the soil with compost or other organic matter to improve soil fertility and drainage.
Cultivation
Pittosporum napaliense Sherff is a slow-growing evergreen shrub that is easy to grow and care for. It can be grown in full sun to partial shade and is hardy in USDA zones 10 and above. The plant prefers well-draining soil and is tolerant of a range of soil types, including acidic, alkaline, and neutral soils.
If you are planning to grow Pittosporum napaliense Sherff in a container, ensure that the container has drainage holes to prevent waterlogging. The plant can be propagated from softwood cuttings taken in late spring or summer.
Watering Needs
The watering needs of Pittosporum napaliense Sherff will vary depending on the season and location. The plant prefers moist soil, but it's essential to avoid over-watering, which can cause root rot. Water the plant deeply once or twice a week during the growing season and reduce watering during the winter months.
If you are growing the plant in a container, water it regularly, but always allow the soil to dry out slightly before watering it again. Check the soil moisture levels by inserting your finger into the soil to a depth of one inch.
Fertilization
Like other plants, Pittosporum napaliense Sherff requires nutrients to thrive. Fertilize the plant with a balanced fertilizer in the spring, followed by a second application in midsummer. Use a slow-release fertilizer to avoid the risk of overfeeding the plant, which can lead to root burn.
The amount of fertilizer required will depend on the size of the plant. Always follow the manufacturer's instructions when applying fertilizer.
Pruning
Pittosporum napaliense Sherff responds well to annual pruning, which helps to maintain its shape and promote dense growth. The best time to prune the plant is in early spring before the new growth appears.
Use clean, sharp pruning shears to remove any dead or diseased wood and thin out any congested growth. Avoid pruning more than one-third of the plant's foliage in a single pruning session. This can cause stress to the plant, reducing its overall health.
Regular pruning helps to keep Pittosporum napaliense Sherff in good shape and promotes healthy growth.
Propagation of Pittosporum napaliense Sherff
Pittosporum napaliense Sherff, commonly known as Napali Shield, is a species of flowering plant that belongs to the family Pittosporaceae. It is a shrub that is endemic to Hawaii and can grow up to 8 meters tall. Propagation methods for Pittosporum napaliense include seed propagation, as well as vegetative propagation through cuttings.
Seed Propagation
The seeds of Pittosporum napaliense are small and black, and can be collected from the mature fruit capsules. The best time for seed harvesting is during the fall months. The collected seeds should be cleaned and soaked in water for 24 hours before sowing. After the seeds have been soaked, they can be planted in a well-drained potting mix, and should be kept moist but not waterlogged.
Germination can take anywhere from 1 to 3 months, and temperature should be maintained at around 21°C to promote successful germination. Once the seedlings have developed a few true leaves, they can be transplanted into individual pots and grown under bright but filtered light. After a year of growth, the young plants can be transplanted into their permanent outdoor location.
Vegetative Propagation
Vegetative propagation of Pittosporum napaliense is achieved primarily through stem cuttings. Stem cuttings should be taken from healthy parent plants during the summer months when new growth is present. The cutting should be around 7-10 cm long and should include at least one node and a few leaves.
The bottom of the cutting should be dipped into rooting hormone, and planted in a well-draining rooting medium such as perlite or vermiculite. The cutting should be kept moist and under bright, indirect light. In several weeks to a couple of months, the cutting should develop roots and can be transplanted to a larger pot or directly into the ground. Success rates for Pittosporum napaliense cuttings can vary, but are typically higher during the summer months when plant growth is at its peak.
Disease Management
One of the common diseases that may affect Pittosporum napaliense Sherff is black spot. It is characterized by the appearance of dark, circular spots on leaves, which eventually turn yellow and fall off. The disease spreads rapidly in wet and humid conditions. To manage black spot, it is vital to remove all the infected leaves and destroy them. You can also use fungicides to prevent further spread of the disease.
Another disease that may attack Pittosporum napaliense Sherff is downy mildew. It is characterized by the appearance of a gray or whitish coating on the leaves' underside, which causes curling of leaves. Downy mildew spreads through splashing water, and hence, it is necessary to water the plant at the base. Fungicides may also help to treat downy mildew.
Pest Management
One of the common pests that may attack Pittosporum napaliense Sherff is the spider mite. The mite sucks the sap from leaves, causing discoloration and drying out of the leaves. To manage spider mites, you can frequently wash the leaves to dislodge them. Also, you can use insecticidal soap to control their spread.
The other pest that may attack Pittosporum napaliense Sherff is the scale insect. The scale insect sucks sap from the leaves, but unlike spider mites, they appear like small bumps on the leaves. To manage scale insects, you can use insecticidal soap or neem oil. You can also scrape off the scales manually, taking care not to damage the leaves.
