Origin
Gouldia terminalis (Hook. & Arn.) Hbd. var. arborescens (Wawra) Fosberg, commonly known as 'Helemano', is a native plant of Hawaii, specifically on the islands of Kauai, Oahu, and Molokai. Historically, it was present in the dry forests on these islands but now has been reduced to a few scattered locations.
Common Names
Besides Helemano, Gouldia terminalis (Hook. & Arn.) Hbd. var. arborescens (Wawra) Fosberg is also commonly called 'Ohe hawai'i, Hawaiian musket tree and Bushman's poison'.
Uses
Although the plant has been used for construction, it’s is not widely utilized. However, there are historical references to its use as a weapon. Hawaiians used the plant to make the poison that was applied to the tip of their spears and arrows. The flowers and roots of the plant are toxic if ingested, containing cardiac glycosides, cardenolides, and oleandrin. These compounds are highly potent and can result in death if consumed in large amounts.
General Appearance
The Gouldia terminalis (Hook. & Arn.) Hbd. var. arborescens (Wawra) Fosberg is an evergreen tree that can grow up to a height of 3 to 5 meters tall, and have branches that extend equally to the ground. Its leaves are thick, leathery, and glossy, and measure around 2-3 cm in length. The flowers of the Helemano tree are small and white and located on the tips of the branches. The bark of the tree is grey and smooth in texture, often peeling in places.
Growth Conditions of Gouldia Terminalis var. Arborescens
Gouldia terminalis var. arborescens is a small to medium-sized evergreen tree with an upright habit, reaching a height of up to 10 meters. It is native to the dry forests and shrublands of the Hawaiian Islands, where it grows in a range of soil types and topographies.
Light Requirements
This species of tree prefers full sun to partial shade for optimal growth and development. It can tolerate some shade, but too much shade can lead to reduced growth rates and a sparser canopy. Therefore, it is best to plant Gouldia terminalis var. arborescens in areas that receive plenty of direct sunlight.
Temperature Requirements
Gouldia terminalis var. arborescens is a tropical species that prefers warm temperatures between 20°C and 30°C. It does not tolerate freezing temperatures and can suffer damage or die if exposed to prolonged periods of cold weather. Therefore, it is best to plant this tree in locations with mild winters and warm summers.
Soil Requirements
This species of tree is adapted to a range of soil types, from sandy to clayey, as long as they are well-draining and not waterlogged. It prefers soils that are rich in organic matter, but it can tolerate poor soils as well. Gouldia terminalis var. arborescens is also adapted to a range of soil pH levels, with a preference for slightly acidic to neutral soils (pH 6.0-7.5). However, it can tolerate mildly alkaline soils as well.
Cultivation Methods
G. terminalis var. arborescens is best grown in well-draining soil, with a pH range of 5.5 to 6.5. It requires full sun to partial shade, preferably in a location with good air circulation. The plant is tolerant of drought and is commonly grown in pots or as a ground cover.
Watering Needs
Water deeply but infrequently, allowing the soil to dry out moderately between waterings. Overwatering can lead to root rot and the plant's death. Watering should be reduced during the winter dormancy period.
Fertilization
G. terminalis var. arborescens can be fertilized twice a year, preferably in the spring and fall. Organic compost or slow-release fertilizers are recommended to prevent overfeeding, which can cause the plant to grow spindly and weak.
Pruning
Prune the plant annually in late winter or early spring when it is still dormant. Cut back the leggy and weak growth, leaving the sturdy and healthy branches. G. terminalis var. arborescens is not a heavy feeder and can thrive without regular pruning.
Propagation Methods for Gouldia Terminalis var. Arborescens
Gouldia Terminalis var. Arborescens is a beautiful plant that can be propagated by seed or vegetative means such as stem cuttings. Here are the propagation methods for this amazing plant:
Propagation by Seed
One of the most common ways of propagating Gouldia Terminalis var. Arborescens is by seed. The seeds should be planted in a well-draining soil mixture and kept moist until they germinate. The plant is known to have a high germination rate, but it may take a few weeks before the seeds sprout.
Once the seedlings have at least three true leaves, they can be transplanted into their own individual containers. The plant should be kept in a warm, bright location, and the soil should be kept moist at all times.
Propagation by Stem Cuttings
Gouldia Terminalis var. Arborescens can also be propagated by stem cuttings. The cuttings should be taken from the plant in the spring or early summer. Use a sharp, clean pair of scissors or pruning shears to take a cutting that is about 3-5 inches long.
Remove the leaves from the bottom of the cutting and dip the cut end into rooting hormone. Place the cutting into a well-draining soil mixture and water it thoroughly. Cover the cutting with a plastic bag or dome to increase the humidity and keep the soil moist.
After a few weeks, the cutting should start to develop roots. Once the roots have formed, the plant can be transplanted into its own individual container. The plant should be kept in a warm, bright location, and the soil should be kept moist at all times.
Propagation of Gouldia Terminalis var. Arborescens can be done successfully using either seed or stem cuttings. No matter which method you choose, make sure to provide the plant with lots of warmth and moisture, and it will thrive.
Disease and Pest Management for Gouldia terminalis var. arborescens
Gouldia terminalis var. arborescens is generally a hardy plant that is not highly susceptible to diseases and pests. However, certain conditions can lead to an infestation or outbreak that can cause damage to the plant. Below are some common diseases and pests that may affect the plant and ways to manage them:
Diseases
Root rot is a fungal disease that can affect Gouldia terminalis var. arborescens if the soil is poorly drained or overwatered. Symptoms of root rot include wilting leaves, yellowing, and root discoloration. To manage root rot, ensure proper drainage of the soil and avoid overwatering. If the disease is severe, remove affected plants and treat the soil with fungicide before replanting.
Leaf spot is another fungal disease that can affect the plant, causing brown or black spots on the leaves. This disease is more common in humid and wet conditions. To manage leaf spot, remove infected leaves and avoid getting water on the leaves. Fungicides can also be used to control the disease.
Pests
Aphids are small insects that can cause damage to Gouldia terminalis var. arborescens by sucking the sap from leaves and stems. They can also cause the growth of mold on the plant. To manage aphids, use insecticidal soap or neem oil. Introducing natural predators like ladybugs can also be effective in controlling the population of aphids.
Thrips are another common pest that can cause damage to the plant by sucking sap from the leaves. They can also cause the leaves to curl and eventually die. To manage thrips, use insecticidal soap or neem oil. Pruning affected leaves and keeping the area around the plant clean can also help to control the population of thrips.
Scale insects can also be a problem for Gouldia terminalis var. arborescens. They can cause a yellowing of the leaves and the growth of sooty mold on the plant. To manage scale insects, use insecticidal soap or neem oil. Pruning affected leaves and using a soft-bristled brush to remove the insects can also be effective in controlling the infestation.
Regular inspection of the plant and early detection of any diseases or pests can help to prevent the spread of infestations and damage to the plant. Using natural methods of pest control and avoiding the use of chemical pesticides can also help to protect the environment and other beneficial insects.
