Overview
Lobelia hillebrandii Rock var. paniculata Rock is a flowering plant species in the family Campanulaceae. It is a subshrub that is native to the Hawaiian Islands.
Common Names
The common names for Lobelia hillebrandii Rock var. paniculata Rock include Hilo Lobelia and Pu‘ohe‘ohe. Some locals also refer to it as simply "Lobelia".
Appearance
Lobelia hillebrandii Rock var. paniculata Rock generally grows to be a small shrub that stands between two and three feet tall. Its leaves are oblong and grow to be about six inches long. The plant produces long, thin, yellow-green or orange-red flowers that grow in a cluster at the end of a stem. The flowers bloom sporadically throughout the year, with the peak blooming season typically occurring in the summer and fall months.
Use
The plant is not widely used for medicinal or culinary purposes, due to its small size and scarcity outside of its native habitat. However, it is sometimes used in Hawaiian lei-making as a filler flower due to its bright color and long-lasting blooms.
Light Requirements
Lobelia hillebrandii Rock var. paniculata Rock prefers bright light or partial shade. It can tolerate direct sunlight, but prolonged exposure may result in leaf scorching. Therefore, it is recommended to grow the plant in a spot where it can receive ample indirect sunlight.
Temperature Requirements
The plant requires a stable temperature, ideally ranging from 15°C to 25°C (59°F to 77°F). It is essential to avoid sudden temperature fluctuations or extreme temperatures, as they can stress the plant and affect its growth and development.
Soil Requirements
Lobelia hillebrandii Rock var. paniculata Rock prefers well-drained soil that is rich in organic matter. The soil's pH level should range from neutral to slightly acidic (6.0 to 7.5) to support optimal growth and blooming. The addition of sand or perlite to the soil can help improve drainage, preventing waterlogging that can damage the roots.
Cultivation Methods
The Lobelia hillebrandii Rock var. paniculata Rock is best planted in well-draining soil on an elevated site that receives full sunlight. It can also survive in partial shade. The plant is propagated by stem cuttings or seed. The plant requires at least six hours of bright light daily.
Watering Needs
While young, the plant requires frequent watering to establish its roots. Once fully established, the Lobelia hillebrandii Rock var. paniculata Rock prefers infrequent deep watering and can tolerate some periods of drought. Overwatering or poor soil drainage is detrimental to the plant's growth and survival.
Fertilization
The Lobelia hillebrandii Rock var. paniculata Rock benefits from light regular fertilization, which stimulates new growth and flowering. Fertilizers rich in phosphorus or low-nitrogen slow-release fertilizers are optimal. Avoid over-fertilizing as this can cause the plant to become leggy, or produce too much foliage instead of flowers.
Pruning
To promote bushy growth and a more compact shape, prune the Lobelia hillebrandii Rock var. paniculata Rock right after flowering. Remove dead, diseased, or weak stems from the base of the plant. Avoid trimming more than a third of the plant at once. Also, remember that the woody stems of the plant are brittle and easily break off, so handle with care.
Propagation of Lobelia hillebrandii Rock var. paniculata Rock
Lobelia hillebrandii Rock var. paniculata Rock, commonly known as the Hawaiian lobelia, is a beautiful flowering plant that is endemic to Hawaii. This plant can be propagated through several different methods, including:
Seed Propagation
Seed propagation is the most common method of propagation for Lobelia hillebrandii Rock var. paniculata Rock. The seeds of this plant can be collected from the parent plant and sown in a well-draining potting mix. It is best to sow the seeds in the spring or summer, and they should germinate within 4-6 weeks.
The seedlings should be kept in a warm, sunny location and watered regularly but not excessively. Once the seedlings are large enough, they can be transplanted into individual pots or directly into the garden.
Cuttings Propagation
Lobelia hillebrandii Rock var. paniculata Rock can also be propagated through cuttings. Taking cuttings in the spring or summer from new growth is recommended. The cuttings should be around 4 inches long and should be taken from non-flowering stems.
The cuttings should be dipped in rooting hormone and placed in a well-draining potting mix. They should be placed in a warm, sunny location and kept moist. The cuttings should root within 2-3 weeks, and once rooted, they can be transplanted into individual pots or directly into the garden.
Division Propagation
Another method of propagation for Lobelia hillebrandii Rock var. paniculata Rock is through division. This is best done in the spring or fall when the plant is not in bloom.
To divide the plant, carefully remove it from the soil and gently separate the root clumps into individual plants. Each divided plant should have a healthy root system and at least one new growth shoot. The divided plants can be planted directly into the garden or in individual pots.
Propagation of Lobelia hillebrandii Rock var. paniculata Rock can be an easy and rewarding process, and using any of the above methods can ensure that you can enjoy this beautiful plant in your garden for years to come.
Disease and Pest Management for Lobelia hillebrandii Rock var. paniculata Rock
Lobelia hillebrandii Rock var. paniculata Rock, also known as Hillebrand's lobelia, is susceptible to various diseases and pests. Here are some of the most common ones:
Diseases
Crown rot: This is a fungal disease that affects the roots and crown of the plant, usually caused by soilborne pathogens. It can cause wilting, yellowing, and eventually death of the plant. To manage this disease, practice good sanitation by removing infected plants and soil. Avoid overwatering and improve soil drainage.
Leaf spot: This is another fungal disease that affects the leaves of the plant. Symptoms include circular brown spots with a yellow halo. To prevent leaf spot, avoid overhead watering and leaf wetness. Remove infected leaves and practice good sanitation by disposing of them properly.
Pests
Spider mites: These tiny pests can cause yellowing and bronzing of the leaves, as well as stunted growth. To manage spider mites, you can wash the leaves with water to remove them, or use insecticidal soap or neem oil spray.
Thrips: These insects feed on the leaves and flowers of the plant, causing curling, distortion, and browning. To manage thrips, use sticky traps or insecticidal soap. You can also encourage natural predators such as lacewings or ladybugs.
Aphids: These sap-sucking insects can cause stunted growth and distortion of the leaves and flowers. To manage aphids, you can use a strong stream of water to wash them off the plant, or use insecticidal soap or neem oil spray.
By practicing good hygiene, monitoring the plant regularly, and using appropriate management techniques, you can keep your Lobelia hillebrandii Rock var. paniculata Rock healthy and free from diseases and pests.
