The Dacrydium cupressinum Sol. ex Lambert
The Dacrydium cupressinum Sol. ex Lambert, also known as the Kahikatea or white pine, is a tall evergreen tree that belongs to the family Podocarpaceae. This plant species is native to New Zealand and can be found growing in lowland forests and wetlands throughout the country.
Common Names
The most popular common name for Dacrydium cupressinum is Kahikatea, which is of Maori origin and translates to "white pine." This name refers to the characteristic white bark of the tree, which stands out prominently in the forest. Other common names for this plant species include New Zealand white pine, blue-leaved kahikatea, and swamp pine.
Uses
Dacrydium cupressinum has several uses in both traditional and modern times. The Maori people of New Zealand utilized the bark of this tree to make clothing and baskets. They also used the wood to create canoes, carvings, and other wooden implements. In modern times, Dacrydium cupressinum is valued for its timber, which is light, strong, and durable. The wood is used in construction, furniture making, and as a veneer. The tree is also planted for ornamental purposes in parks and gardens around the world.
General Appearance
The Dacrydium cupressinum Sol. ex Lambert is a tall evergreen tree that can grow up to 65 meters in height. It has a straight trunk, which is usually free of branches for the first 20 meters or more. The crown of the tree is conical, with the lower branches drooping downwards. The bark of the tree is creamy-white and has a scaly texture. The leaves are scale-like and are bright green in color, arranged in a spiral pattern around the stem. The plant is dioecious, meaning it has separate male and female trees. The female trees produce small, red, and fleshy fruits that are bird-dispersed.
Light Requirements
The plant Dacrydium cupressinum, commonly referred to as the New Zealand Rimu, prefers partial shade to full sun as its ideal light condition. It can thrive under direct sunlight but requires a well-shaded environment to grow to its full potential.
Temperature Requirements
It is important to note that the New Zealand Rimu thrives in a wide range of temperatures. However, it can withstand average temperatures ranging from 2°C (35.6°F) in winter to 15-20°C (59-68°F) in summer. This makes it an ideal plant to grow in an area with a variable climate, as it can adjust accordingly.
Soil Requirements
The Dacrydium cupressinum plant requires adequate soil moisture to grow. It needs well-draining soil, preferably with a pH of 4.5 to 6.5, which is slightly acidic. The soil should be nutrient-rich and contain high levels of organic matter.
Additionally, the plant can tolerate variations in soil composition, from sandy to clayey soils. However, it does not grow well in waterlogged or alkaline soils. Therefore, the soil condition should be well-drained and moistened, but not soaked with water.
Cultivation of Dacrydium cupressinum Sol. ex Lambert
The Dacrydium cupressinum, also known as Rimu, is a slow-growing evergreen tree found in New Zealand. It prefers well-draining soil with a slightly acidic pH, but it can tolerate a range of soil types. To cultivate the plant, ensure it is planted in a location that receives full sunlight or partial shade.
Watering Needs of Dacrydium cupressinum Sol. ex Lambert
The watering needs of the Dacrydium cupressinum depend on the climate and soil type. In areas with dry climates, the plant will require more frequent watering, whereas in areas with high rainfall, the plant may require less watering. A general rule of thumb is to water the plant deeply but infrequently. Ensure the soil is moist but not waterlogged, as the plant does not tolerate waterlogging well.
Fertilization of Dacrydium cupressinum Sol. ex Lambert
The Dacrydium cupressinum does not require frequent fertilization and can survive well without it. However, if you want to encourage rapid growth or address nutrient deficiencies, you can fertilize the plant during the growing season. Use a balanced fertilizer with a 2:1:1 or 3:1:2 ratio of nitrogen, phosphorus, and potassium.
Pruning of Dacrydium cupressinum Sol. ex Lambert
The Dacrydium cupressinum does not require pruning, but it can be done to remove any diseased or damaged branches or to shape the plant. Prune during the dormant season when the plant is not growing, as this will reduce the risk of damaging new growth. Use clean and sharp pruning tools to avoid damaging the plant, and always prune above a healthy node or bud to encourage new growth.
Propagation of Dacrydium cupressinum Sol. ex Lambert
Propagation is an important aspect in the cultivation of Dacrydium cupressinum Sol. ex Lambert. There are several methods that can be used to propagate this plant, including:
Seed Propagation
Seed propagation is the most common method of propagating Dacrydium cupressinum. Seeds can be collected from the cones of the plant. The seeds are then cleaned and stored until they are ready to be used. Before planting, the seeds need to go through a stratification period, where they are kept in a cool, damp environment for several months. This process helps to break down any inhibitors that prevent the seed from germinating.
Once this period is over, the seeds can be planted in seed trays, with a mix of peat moss and sand. The trays should be kept moist and placed in a location with bright, indirect light. The seedlings take around 3-6 months to germinate, and once they are around 10cm tall, they can be transplanted into individual pots.
Cuttings Propagation
Dacrydium cupressinum can also be propagated through cuttings. The best time to take cuttings is during the summer when the plant is actively growing. Softwood cuttings are the best type to take for propagation. Take cuttings that are around 10cm long, with a few leaves attached, and remove any leaves from the bottom half of the cutting.
Dip the cut ends of the cuttings into rooting hormone, and then plant them in a mix of peat moss and sand. The cuttings should be kept in a warm, humid environment with bright, indirect light. It may take several weeks to a few months for the cuttings to start rooting, and once they have rooted, they can be transplanted into individual pots.
Grafting Propagation
Grafting is another propagation method that can be used for Dacrydium cupressinum. This method involves taking a cutting from one plant, and grafting it onto another plant's rootstock. This is a more complex method of propagation and requires more skills and knowledge than seed or cutting propagation.
In conclusion, there are several methods of propagation for Dacrydium cupressinum, including seed propagation, cuttings propagation, and grafting propagation. Growers should choose the method that is most suitable for them based on their skills, experience, and the resources that they have available.
Disease Management
Dacrydium cupressinum Sol. ex Lambert or Kahikatea is a coniferous tree that can be affected by several diseases. Some of the common diseases that affect this plant are:
- Phytophthora rots: These rots are caused by the pathogen Phytophthora. The symptoms include wilting, leaf spots, and root decay. To manage these rots, avoid over-watering, and make sure the soil drains well. Remove and destroy the affected plant parts.
- Canker and dieback: These are fungal diseases that cause twig and branch dieback. The symptoms include cankers and brown discoloration of the bark. To manage canker and dieback, prune the infected branches and dispose of them properly. Protect the trees from wounds and maintain proper nutrition.
- Needle blight: This disease is caused by the fungus Mycosphaerella. The symptoms include yellowing and browning of the needles. To manage needle blight, use resistant varieties, prune the infected branches, and remove the fallen needles and other plant debris.
Pest Management
Dacrydium cupressinum can also be attacked by several pests. Some common pests that attack this plant are:
- Cypress bark beetle: The larvae of this beetle tunnel into the bark, causing extensive damage. The symptoms include wilting and yellowing of the foliage. To manage this pest, keep the tree healthy and free from other pests and diseases. Infested trees should be removed and destroyed.
- Scale insects: These insects feed on the sap of the tree, causing yellowing and wilting of the foliage. The symptoms include sticky honeydew on the leaves and branches. To manage scale insects, prune the infected branches and use horticultural oil or soap to control the population.
- Mealybugs: These insects also feed on the sap of the tree. The symptoms include yellowing and wilting of the foliage and the presence of white, cottony masses on the leaves and branches. To manage mealybugs, prune the infected branches and use horticultural oil or soap to control the population.
