How to grow a Norfolk Island pine? A detailed guide to the latest cultivation methods
The Norfolk Island pine is also known as the heterophyllous Araucaria, Norfolk Island Araucaria, fine-leaved Araucaria, etc. It is an evergreen tree of the genus Araucaria in the family Araucariaceae, native to the southeastern coastal regions of Oceania, and is now introduced and cultivated in Guangdong and other provinces. Some cities in northern China began introducing Norfolk Island pine bonsai in 2002, and they have grown well. Now let us take a look at the cultivation methods for the Norfolk Island pine!
Growth habits of the Norfolk Island pine
Potted Norfolk Island pines are generally young trees, under 2 m tall, with a spire-shaped crown, dark green color, upright stems, whorled side branches spreading horizontally, and branchlets alternately arranged in two rows, extending horizontally or slightly drooping, with two types of leaves. The cones are nearly round. It likes warm, humid environments and grows well in places with ample sunlight. It has a certain tolerance for shade, but should avoid strong sunlight exposure in summer. It is not tolerant of cold or drought, and is suitable for well-drained, humus-rich, slightly acidic sandy loam.
Propagation methods of the Norfolk Island pine
1. Sowing: Seedlings grown from seed of the Norfolk Island pine are sturdy and strong, growing vigorously, and are suitable for mass propagation. Generally, in July to August, first scarify the seed coat of freshly collected seeds to promote germination; otherwise, if left in the soil too long, the seeds are prone to rot. Then sow the treated seeds in a sand bed, covering with fine sand about 1.5-2 cm. Under conditions of 25-28°C and a certain humidity, they will germinate in about 2-3 weeks, and should be planted immediately after germination.
2. Cuttings: When taking cuttings of the Norfolk Island pine, if the main axis or a vigorous shoot is chosen as the cutting, it easily causes the plant's crown shape to be irregular and able to grow only sideways, affecting its ornamental value. Cut the easily rooting, healthy branch tips with 2-3 nodes as cuttings, remove some leaves, soak overnight in clean water, then insert them into a sand bed with coarse sand or vermiculite as the substrate. Maintain a temperature of 20-25°C and relatively high air humidity, and they will root after about 3 months.
Cultivation methods of the Norfolk Island pine
1. Soil: The Norfolk Island pine is suitable for well-drained, humus-rich, slightly acidic sandy loam. When potting, a substrate mixed from garden soil, leaf mold, and peat moss is best.
2. Watering: From spring to autumn, the Norfolk Island pine should be watered more, but avoid water accumulating in the pot. During high temperature and dryness, spray water on the potted plant and nearby ground to cool and increase humidity. Water promptly; do not wait until the soil dries before watering. From late autumn onward, gradually reduce watering to enhance its cold resistance.
3. Light: The Norfolk Island pine likes diffused light and should be placed in a bright spot inside a shed. If kept in a dark place for a long time, it should be moved into sunlight every few weeks for appropriate exposure, which can keep the dark green leaves with a beautiful color.
4. Temperature: The Norfolk Island pine has a long growing season and can grow all year except when the summer temperature exceeds 32°C.
5. Fertilizing: During the growing season, the Norfolk Island pine should be given a supplementary fertilizer every 2 weeks, preferably a compound fertilizer containing nitrogen and potassium. Insufficient fertilizer supply easily causes the branches and leaves to turn yellow.
6. Pests and diseases: The Norfolk Island pine has very few pests and diseases. When maintained indoors, scale insects are commonly seen; spraying methidathion, chlorpyrifos EC, Guoguang Jie Bisi, etc. for control gives good results.
Precautions for cultivating the Norfolk Island pine
1. The Norfolk Island pine grows in summer and autumn. Potted plants can be placed in a semi-shaded spot outdoors, or kept in a ventilated place with light near a window. Avoid blazing sun exposure above 35°C, and do not leave it for long in a lightless, shaded place. Either will cause the branches and leaves to turn yellow or grow leggy, affecting ornamental value.
2. During the growth of the Norfolk Island pine, to avoid the trunk leaning to one side, it is best to turn the pot once every half month so the plant receives light evenly. In addition, the trunk of young trees is fragile and easily bends and deforms, so it is best to set up a support from the young stage to fix the trunk. To prevent the plant from growing too tall, it should be repotted once every 2-3 years after spring warms up. Usually, take care to protect the side branches so they are not damaged and affect the plant shape.
3. Under normal conditions, the Norfolk Island pine does not need pruning of branches; let it grow naturally. The suitable growth temperature is 10-25°C, and the overwintering temperature is above 5°C. During the overwintering season, give it a certain amount of light, and the potting soil should not be too dry. On clear days, water should also be sprayed to increase humidity.