The Norfolk Island Pine is indigenous to Norfolk Island, which lies in the South Pacific Ocean between Australia, New Zealand, and New Caledonia. This small island, approximately 3.5 miles wide and 5 miles long, is a unique ecosystem where the pine has adapted to its specific conditions.
The plant was first documented by Europeans during Captain James Cook’s second voyage in 1774. Captain Cook named the island after the Duchess of Norfolk, and his botanist, David Nelson, collected specimens of the pine, noting its potential ornamental value.
Originally, the species was named Araucaria excelsa by botanist Jean-Baptiste Lamarck in 1788, based on Cook’s collections. However, it was later correctly identified and renamed Araucaria heterophylla by Brongniart in 1842, reflecting its unique leaf characteristics (“heterophylla” means different leaves).
On Norfolk Island, these trees grow in the moist, subtropical climate, often near the coast where they can benefit from the sandy, well-draining soils and the high humidity. They are part of the island’s ancient forest, with some trees reaching ages over 200 years.
The Norfolk pine tree (Araucaria heterophylla) isn’t a true pine. In fact, while most true pines tolerate freezing temperatures, this South Pacific region native prefers warmer climates, including those found in U.S. Department of Agriculture plant hardiness zones 10 and 11. This slow-growing tree reaches up to 100 feet in height and features pointy, light green leaves, a distinct pyramidal shape and large, spiny cones.
The Norfolk pine (Araucaria heterophylla) remains smaller indoors, often serving as a potted holiday tree during the Christmas season. It usually is grown as a houseplant. You can propagate the tree most easily from seeds or air-layering. Cuttings are more problematic.
Characteristics of the Norfolk Island Pine (Araucaria heterophylla)
- Appearance and Structure: The Norfolk Island Pine has a distinctive, symmetrical, conical shape that often resembles a perfect Christmas tree. It features horizontal branches which are arranged in regular whorls around the trunk, giving it an almost artificial, tiered look.
- Foliage: Its foliage consists of scale-like leaves that are dark green and closely packed, giving the plant a dense, lush appearance. The leaves are small, triangular, and overlap each other, creating a prickly feel when touched, but they are not as sharp as many conifers.
- Growth Habit: This species is slow-growing when kept indoors but can reach up to 200 feet (60 meters) in its natural habitat. As a houseplant, it typically grows to about 3 to 6 feet (0.9 to 1.8 meters) over several years under ideal conditions.
- Native Environment: Native to Norfolk Island in the South Pacific, it thrives in a subtropical climate with high humidity. In its natural habitat, it’s often found near the coast, which influences its preference for well-draining, sandy soils.
- Light Requirements: It prefers bright, indirect light. Direct sunlight can scorch its foliage, while too little light can result in sparse, elongated growth. It’s best placed near a window with a sheer curtain to filter the light.
- Watering Needs: The Norfolk Island Pine requires regular watering but is susceptible to root rot if overwatered. The soil should be kept evenly moist but not waterlogged. During the growing season, watering once a week is often sufficient, with reduced frequency in winter.
- Humidity Preference: As a tropical plant, it favors high humidity. In dry indoor environments, misting the foliage or using a pebble tray with water can help maintain appropriate humidity levels. Low humidity can lead to brown leaf tips.
- Soil and Fertilization: It does best in a well-draining, slightly acidic soil mix with some sand or perlite added for drainage. Fertilize monthly during the spring and summer with a balanced, water-soluble fertilizer at half strength to avoid over-fertilizing.
- Temperature and Climate: It prefers temperatures between 60-72°F (16-22°C). It’s sensitive to cold, with temperatures below 50°F (10°C) potentially causing damage. Therefore, it’s not suited for outdoor living in temperate or cold climates unless protected.
- Pests and Problems: While generally hardy, it can be prone to pests like spider mites, scale, and mealybugs, especially in dry conditions. Regular inspection and maintaining proper humidity can prevent
Propagation of Norfolk Island Pine (Araucaria heterophylla)
Seed Propagation
- Seed Collection: Seeds can be collected from mature cones on the tree. However, this is rarely practical for home growers since the tree rarely produces cones indoors, and even in its natural environment, it might take years or decades for the tree to reach reproductive maturity.
- Seed Preparation: Seeds should be cleaned and dried. They have a hard outer shell which might require soaking in water for 24-48 hours to soften before planting.
- Sowing: Use a well-draining seed starting mix. Plant the seeds about 1 inch deep in small pots or seed trays. Keep the soil moist but not waterlogged.
- Germination: Seeds can take several weeks to months to germinate, often requiring a warm environment (around 70-80°F or 21-27°C) and high humidity. A propagator or plastic cover can help maintain these conditions.
- Care of Seedlings: Once sprouted, seedlings need bright, indirect light. Gradually introduce them to more light to prevent burning. Keep the soil consistently moist, and once the seedlings have a few sets of leaves, they can be transplanted into individual pots with a well-draining potting mix.
Cuttings
- Selecting Cuttings: Propagation via cuttings is less common and less successful with Norfolk Island Pine but can be attempted. Choose semi-hardwood cuttings, about 6-8 inches long, from new growth in late spring or early summer.
- Preparation: Cut just below a node, remove the lower leaves to expose a few inches of stem for planting. Some gardeners dip the cut end in rooting hormone to encourage root development.
- Planting: Use a mix of peat moss and perlite or a similar well-draining medium. Insert the cutting into the mix, ensuring no leaves are buried.
- Environment: Cover with a plastic bag or dome to create a mini greenhouse effect, maintaining high humidity. Place in indirect light.
- Rooting: Rooting can take several months, and success is not guaranteed. Keep the medium slightly moist, and occasionally ventilate to prevent mold growth. If roots form, which you can check by gently tugging on the cutting to feel resistance, the cutting can be moved to a pot with regular potting soil.
Air Layering
- Rarely Used: Air layering is not commonly practiced with Norfolk Island Pine but could be theoretically possible. This involves wounding a branch, applying rooting hormone, covering the wounded area with moist sphagnum moss, and then wrapping it with plastic to retain moisture until roots develop.
- Process: Choose a healthy branch, make an upward cut about one-third into the wood, apply rooting hormone, wrap with damp sphagnum moss, and encase this with plastic, securing both ends. Roots should appear in several months, after which the new plant can be cut off below the root mass and potted.
Challenges and Tips:
- Slow Growth: All methods require patience as Araucaria heterophylla grows slowly, especially from seed.
- High Humidity: Maintaining the right humidity levels is crucial for success in propagation, particularly for cuttings.
- Light and Temperature: Consistent warm temperatures and bright, indirect light are necessary for rooting and growth.
- Disease and Pests: Be vigilant for fungal issues due to the high moisture environment needed for propagation.