Do you have Araucaria Heterophylla as an indoor potted plant and you don’t know how to take care of it? Here you will get a care guide on Araucaria Heterophylla as an indoor potted plant. These plants are very cute and little house plants which are also popular as Christmas trees and people buy them all around the World during winter holidays. Following are the recommended care for your plant.
I. Appearance and Characteristics
Araucaria heterophylla (synonym A. excelsa) is a species of conifer. As its vernacular name Norfolk Island pine (or Norfolk pine) implies, the tree is endemic to Norfolk Island, an external territory of Australia located in the Pacific Ocean between New Zealand and New Caledonia. It is not a true pine, which belong to the genus Pinus in the family Pinaceae, but instead is a member of the genus Araucaria, in the family Araucariaceae, which also contains the hoop pine. Members of Araucaria occur across the South Pacific, especially concentrated in New Caledonia (about 700 km or 430 mi due north of Norfolk Island) where 13 closely related and similar-appearing species are found. It is sometimes called a star pine, Polynesian pine, triangle tree or living Christmas tree, due to its symmetrical shape as a sapling.
The tree is slow growing and can reach a height of 50–65 m (160–210 ft), with straight vertical trunks and symmetrical branches, even in the face of incessant onshore winds that can contort most other species. From the straight trunk, it emits five almost horizontal or slightly oblique branches, forming floors; the plane of each floor is a perfect pentagon. If kept indoors, the tree remains smaller. The gray-brown bark falls off in fine scales. The branchlets are four to seven in regular whorls.
The young leaves are soft and awl-shaped, 1–1.5 cm (0.4–0.6 in) long, about 1 mm (0.04 in) thick at the base on young trees, and incurved, 5–10 mm (0.2–0.4 in) long and variably 2–4 mm (0.1–0.2 in) broad on older trees. The thickest, scale-like leaves on coning branches are in the upper crown. The cones are squat globose, 10–12 cm (4–5 in) long and 12–14 cm (5–6 in) diameter, and take about 18 months to mature. They disintegrate at maturity to release the nut-like edible seeds. The seeds have a length of 2.5 to 3 cm (1.0 to 1.2 in) and a diameter of about 1.2 cm (0.5 in) with wide wings. There are four cotyledons present. It is a dioecious tree (male and female flowers in different plants), although it can also be monoecious.
The scientific name heterophylla (“different leaves”) derives from the variation in the leaves between young and adult plants.
II. How to Grow and Care
Sunlight
A Norfolk Island pine needs sun, preferring full sun whenever possible. Norfolk Island pines can also handle relatively long periods (months at a time) in dimmer conditions. Thus, you can keep your potted plant indoors during the winter and then move it to a sunny spot outdoors when the summer comes around.
If your plant begins to stretch while growing inside, the odds are that the combination of low light and heavy fertilizer is causing leggy growth. In that case, cut back on the fertilizer until the plant has more access to sunlight. It’s helpful to turn it frequently, so every side gets equal light.
Temperature
Araucaria Heterophylla as an indoor potted plant is a tropical plant and is not cold hardy. These plants can neither tolerate very high temperatures, nor very cold. The ideal temperature range during the warm period is nothing above 20 degrees Celsius. Wintertime between 10 -15 degrees Celsius. Due to its sensitivity to the temperature, it is recommended to plant them in covered areas or indoors. However, it is also recommended to keep them near windows to ensure the availability of bright light.
Humidity
Being a tropical plant Araucaria Heterophylla as an indoor potted plant needs high humidity. During the winters these plants face the great issue of humidity. Switching on central heating dries air too much for it resulting in significant indoor humidity fall. Thus it is recommended to use Pebble tray with water or humidifier to keep humidity high around the plant or just daily spray of water will do just fine.
Watering
Keep your Norfolk Island pine moderately moist in spring, summer, and fall using water with a low lime content. You should water Araucaria heterophylla more sparingly in winter. It is best to water the plant with rainwater. Norfolk Island pine also likes to be sprayed with water on a regular basis. You should avoid water logging at all costs: Otherwise the container plant will lose its needles very quickly.
Soil
Plant in soil that is rich, sandy, and acidic. These are acid-loving plants, preferring a pH in the 4.5-5.5 range. You can check your soil pH with an easy-to-do test, which will help keep your tree happy and healthy for a long time.
Fertilizing
You should fertilize Norfolk Island pine with a liquid fertilizer every two weeks in spring and summer. Products suitable for rhododendrons and hydrangeas are ideal, as they are reliably lime-free. The tree does not generally need any nutrients in cool locations between November and February. If the Norfolk Island pine is in a warmer place, you should continue to fertilize it every four to six weeks at a slightly lower concentration.
Pruning
Remove lower branches that have died—a common issue with indoor specimens. It is usually not recommended to trim the top of the tree, but if a potted tree gets too large for its space, cut off the central leader. This will cause the tree to branch out from that point, and while the plant will lose the classic evergreen look, such trimming usually does not affect the health of the tree.
Remove dead and diseased branches from trees grown outdoors, but other than this, no routine pruning is necessary.
Propagation
Hobby gardeners tend to find Norfolk Island pine very difficult to propagate. The best way to do this is by sowing seeds, however it’s not that easy to get hold of them. You may be able to pick them up while on vacation, as Norfolk Island pines are planted on the Canary Islands and throughout nearly all of the Mediterranean region as garden trees. However, you should check the legal regulations before exporting. Since Araucaria heterophylla seeds quickly lose their ability to germinate, you should sow them as soon as you get them. The seeds germinate at a soil temperature of around 65 to 68 degrees Fahrenheit.
Vegetative propagation by terminal cuttings is another option, but this is also very difficult and long-winded. You should only use shoot tips for cuttings, as they retain the typical growth habit. The cuttings needs high temperatures between 77 and 86 degrees Fahrenheit to form roots. Most of the Norfolk Island pines available in stores are now obtained from meristem culture, a complex propagation process that takes place under sterile conditions in a lab.
Potting and Repotting
A potted Norfolk Island pine only needs to be repotted when it’s root-bound or the roots are beginning to come out of the drainage hole. Young Norfolk Island pines are not very fast growers, so it might be possible to repot your tree every other year instead of every year. As the plant matures, it will begin to grow faster.
Repot your Norfolk Island pine in the springtime, and if your plant has attained a larger size, make sure to use a pot of any material with plenty of heavy items in the mix, such as potting sand, to provide enough weight to keep the plant upright. It will do best in peaty, sandy potting mix that is slightly acidic. Make sure the pot is only a couple of inches larger than the one the plant is coming from, but also make certain it has plenty of drainage holes.
Overwintering
Norfolk pines love the warm weather and can’t tolerate temperatures below 35 degrees Fahrenheit. When it is faced with frost, the plant will begin to yellow and die.
Bring a potted tree indoors if it’s not already, and keep it away from drafts. Place it in a room with high humidity (difficult to do in a dry home during the winter) and full, bright sunlight. Water only when the surface of the soil is dry to the touch.
Pests and Diseases
Common Pests & Plant Diseases
Norfolk Island Pines are vulnerable to pests including aphids, mealybugs, scale, mites, and whiteflies.3 If possible, identify the infestation as early as possible and treat it with the least toxic option. A Norfolk pine may also develop a fungal disease from overwatering, such as anthracnose, which can turn entire sections of the tree yellow, brown, and then cause the plant to die.
Common Problems With Norfolk Island Pines
This easy-going tree may encounter a few challenges in its life. The needles will turn different colors to alert you to a problem.
Needles Turning Brown
The tree can’t tolerate cold, but it also can’t tolerate extreme heat. Wide temperature fluctuations can cause the needles to brown. Brown needles may also indicate that the plant is being overwatered or underwatered, too.
Needles Turning Yellow
If the needles turn yellow, the tree may not be getting enough sunlight. Or, it could be getting too much sunlight. Extreme changes in temperature may also be the culprit turning the needles yellow.
Needles Dropping
Needles will drop for two reasons: Your tree is either being overwatered or it’s not given enough light.
III. Uses and Benefits
Young trees are often grown as houseplants in areas where the winters are too cold for them to grow outside (they will not, for example, survive outdoors in most of North America or Europe), and are sometimes used as Christmas trees.
Araucaria heterophylla has gained the Royal Horticultural Society’s Award of Garden Merit.
