Australian Pine: How to Grow and Care

Australian Pine, also known as Norfolk Island Pine, heterophyllous Araucaria, and fine-leaved Araucaria, is an evergreen tree of the genus Araucaria in the family Araucariaceae. It is native to the southeastern coastal regions of Oceania, and has now been introduced and cultivated in Guangdong and other provinces. Some cities in northern China began introducing Australian Pine bonsai in 2002, and they have grown well. Let's take a look at how to grow Australian Pine!

Growth Habits of Australian Pine

Potted Australian Pines are generally young trees, under 2 m tall, with a pointed tower-shaped crown, dark green color, upright stems, whorled lateral branches spreading horizontally, and small branches alternately arranged in two rows, extending horizontally or drooping slightly, with two types of leaves. The cones are nearly round. It prefers warm, humid environments and grows well in sunny spots. It has some tolerance for shade, but should be protected from strong sunlight in summer. It is not tolerant of cold or drought, and is suited to well-drained, humus-rich, slightly acidic sandy loam.

Propagation Methods of Australian Pine

1. Sowing: Seedlings grown from seed are sturdy, strong, and vigorous, making sowing suitable for batch propagation. Generally, from July to August, freshly collected seeds should first have their seed coats nicked to promote germination; otherwise, if left in soil too long, the seeds tend to rot. Then sow the treated seeds in a sand bed, covering with fine sand about 1.5-2 cm deep. Under conditions of 25-28°C and a certain level of humidity, they will germinate in about 2-3 weeks. Plant them immediately after germination.

2. Cuttings: When taking cuttings of Australian Pine, if the main axis or a leggy branch is chosen as the cutting, it easily causes the plant's crown shape to become irregular, growing only horizontally and reducing its ornamental value. Cut 2-3 nodes from the tip of a healthy, easy-to-root branch as the cutting, remove some leaves, soak in clean water overnight, then insert into a sand bed with coarse sand or vermiculite as the medium. Maintain a temperature of 20-25°C and high air humidity; roots will form in about 3 months.

How to Grow Australian Pine

1. Soil: Australian Pine is suited to well-drained, humus-rich, slightly acidic sandy loam. For potting, a medium made by mixing garden soil, leaf mold, and peat moss is best.

2. Watering: From spring to autumn, Australian Pine should be watered frequently, but waterlogging in the pot must be avoided. In hot, dry conditions, spray water on the potted plant and the nearby ground to lower the temperature and increase humidity. Water promptly; do not wait until the soil dries out before watering. From late autumn onward, gradually reduce watering to strengthen its cold resistance.

3. Light: Australian Pine likes diffused light and should be placed in a bright spot in a shed or greenhouse. If kept in a dark place for a long time, move it into sunlight every few weeks for appropriate exposure, which will keep the dark green leaves a beautiful color.

4. Temperature: Australian Pine has a long growing season and can grow year-round except when summer temperatures exceed 32°C.

5. Fertilizing: During the growing season, apply fertilizer every 2 weeks, preferably a compound fertilizer containing nitrogen and potassium. Insufficient fertilizer easily causes the branches and leaves to turn yellow.

6. Pests and diseases: Australian Pine has very few pests and diseases. When kept indoors, scale insects are commonly seen; spray with methidathion, chlorpyrifos emulsifiable concentrate, Guoguang Jiebitsi, etc. for control, with good results.

Precautions for Growing Australian Pine

1. Australian Pine grows in summer and autumn. Potted plants can be placed in a semi-shaded spot outdoors, or kept in a ventilated spot with light near a window. Avoid exposure to blazing sun above 35°C, and do not leave it in a lightless, shaded place for long. Either will cause the branches and leaves to turn yellow or become leggy, reducing its ornamental value.

2. During the growth of Australian Pine, to prevent the trunk from leaning to one side, turn the pot once every half month so the plant receives light evenly. In addition, young tree trunks are fragile and easily bent and deformed, so from the young seedling stage a support should be set up to fix the trunk. To prevent the plant from growing too tall, repot once every 2-3 years after the weather warms in spring. Normally, take care to protect the side branches so they are not damaged, which would affect the plant's shape.

3. Under normal conditions, Australian Pine does not need branch pruning; let it grow naturally. The suitable growing temperature is 10-25°C, and the overwintering temperature is above 5°C. During the winter, give it some light, do not let the potting soil get too dry, and spray water on clear days to increase humidity.