Norfolk island pine pruning

Norfolk Island Pine – The Other Living Christmas Tree


Norfolk Island Pines make great tabletop trees for offices, apartments or anywhere space does not allow a larger tree.

By Cindy Haynes
Horticulturist
Iowa State University Extension

When people think of living Christmas trees they often think about small, container-grown evergreens that are brought indoors around Christmas. Their time indoors must be short, and a well-planned exit strategy (hole already dug in the landscape) should be in place. Obtaining and attempting to ensure winter survival of such a tree can be a lot of work for a limited amount of enjoyment indoors.

The Norfolk Island Pine (Araucaria heterophylla) is another option for having a live Christmas tree during the holiday season. This tree is quite different from a typical pine in the Iowa landscape. It is a tropical plant, and must remain indoors during the winter months. As the name suggests, it is native to the Island of Norfolk, a tiny island near New Zealand. In its native habitat it will easily reach more than100 feet tall — thankfully, it rarely reaches more than 20 feet tall inside most homes.

Pros and Cons of the Norfolk Island Pine
This time of year you see small Norfolk Island Pines for sale in some nurseries, garden centers, discount stores and even grocery stores. They often have tiny velvet bows or bells attached to the branches in place of ornaments. They make great tabletop trees for offices, apartments or anywhere space does not allow a larger tree. Over time, as they grow and get larger they can approach heights and widths normally found with regular Christmas trees.

While they can get large enough to become trees, their branches cannot usually sustain the weight of most holiday ornaments. Smaller ornaments and mini-lights are recommended when decorating Norfolk Island pines. It also is recommended that the decorations be removed promptly after the holiday season to prevent damage to the needles or branches.

The biggest advantage of a Norfolk Island pine is that it can grow indoors for many years. They prefer bright, mostly indirect light from eastern or western windows. They are temperamental with respect to soil moisture — never wanting to be too wet or too dry. Consistent and thorough watering when the top of the soil dries out will help ensure longevity. Increased humidity in the winter also is necessary to keep plants thriving indoors.

Provided that the tree is properly placed and watered, Norfolk Island pines are fairly easy to maintain, preferring more neglect than nurture. They require little fertilization — watering with a soluble fertilizer once a month in spring and summer should be sufficient. They also prefer to be a bit pot-bound, meaning they do not require repotting every year. Repotting into a slightly larger container with a well-drained commercial potting mix every four years should be adequate.

Norfolk Island pines also will let you know if something is wrong in their environment. If environmental conditions do not meet their liking, the lower limbs may turn yellow or brown and fall off prematurely.

These attractive indoor trees lend themselves nicely to decorating each holiday season. Try one out in your home this holiday and watch how quickly it will become an important part of your future holiday family traditions.

There is one photo for this week’s column:
Norfolk113007.jpg – Norfolk Island pines make great tabletop trees for offices, apartments or anywhere space does not allow a larger tree.

Norfolk Island Pine Pruning: Information On Trimming A Norfolk Island Pine

If you have a Norfolk Island pine in your life, you may well have purchased it as a live, potted Christmas tree. It is an attractive evergreen with feathery foliage. If you want to keep the container tree or transplant it outdoors, you may want to know about pruning of Norfolk Island pine trees. Should you prune a Norfolk Island pine? Read on to learn the ins and outs of Norfolk Island pine pruning.

Cutting Back Norfolk Island Pines

If you bought the tree for the holidays, you are not alone. Norfolk Island pines are often used as living Christmas trees. If you decide to keep the tree as a container tree, it will need some water, but not too much water. Norfolk Island pines need moist soil but will die in wet soil.

Your Norfolk Island pine will also require as much light as you can offer. It accepts direct or indirect light, but does not like to be close to heaters. If you adapt this container plant for the long term, you’ll need to change the container every three years or so using a classic potting mix.

Should you prune a Norfolk Island pine? You will definitely need to start cutting back Norfolk Island pines when the lower branches die. Norfolk Island pine pruning should also include snipping out multiple leaders. Just leave the strongest leader.

Pruning of Norfolk Island Pine Trees

If your Norfolk Island pine doesn’t get enough water or enough sunlight, its lower branches are likely to die back. Once they die, they will not grow back. While all maturing trees will lose some lower branches, you’ll know the tree is distressed if a lot of branches die. You will need to figure out what conditions are distressing the tree.

It’s also time to think about Norfolk Island pine pruning. Trimming a Norfolk Island pine will include removal of dead and dying branches. Sometimes, Norfolk Island pines drop so many branches that only bare trunks remain with tufts of growth at the tip. Should you prune a Norfolk Island pine’s trunks in these conditions?

While it’s entirely possible to start trimming a Norfolk Island pine trunk that has lost most of its branches, it may not yield the result you seek. Norfolk Island pine pruning will distort the tree. Pruning of Norfolk Island pine trees in this situation will probably produce multi-stemmed, shrubby plants.

Dealing With Your Ginormous Norfolk Island Pine

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The question isn’t whether that Norfolk Island pine you were given at Christmas will press against your ceiling. The question is when.

Not a true pine, Norfolk Island pine (Araucaria heterophylla) is a beautiful evergreen tree named for its native home of Norfolk Island off the coast of Australia. It’s hardy outdoors in places like south Florida where it doesn’t freeze in winter, but most of us grow it as a houseplant. We prize it for its symmetrical shape and graceful, evenly spaced whorls of branches that bear soft, shiny needles. Many people decorate it as an indoor Christmas tree. Others simply value it as a statuesque touch of the tropics.

It’s that “statuesque” part that’s often the problem. See, in the wild Norfolk Island pine wants to grow 80 feet tall. It still wants to do that inside your house. This poses difficulties for folks who don’t have 80-foot ceilings.

WATCH: 10 Plants That Will Take Over Your Yard

Thus, Norfolk Island pine eventually grows too tall for most houses. That’s when people turn to Grumpy, seeking solutions.

The first solution is obvious. Throw it away and start over with a small one. But that might strike you as heartless, as the population of homeless Norfolk Island pines continues to swell and strain local resources.

The second solution is just as obvious. Reduce it to a more manageable size by pruning. Here’s how to do this.

First, decide how tall your want your tree to be. Then cut back the top to that height just above a complete whorl of branches. The tree will resume growing from that point.

Now, shorten the side branches to restore the tree’s symmetrical shape lost by shortening the top. The shortest branches should be at the top, the longest ones at the bottom, and the middle ones in-between, so that the end product looks something like a Christmas tree.

Whatever you do, don’t cut a hole in the ceiling. You’ll soon regret it and take your resentment out on the tree. And you’ll still have a stupid hole up there.

Growing Tips

Norfolk Island pine needs bright light. Place it near the sunniest windows in your house. If the light isn’t bright enough, the tree will drop its lower branches and not replace them, and you will have one homely looking houseplant.

The plant also likes humid air, as most tropical plants do. People don’t, however, so indoor air is typically bone dry. Help out your Norfolk Island pine by misting the foliage a couple of times a day or placing it atop a pebble-lined saucer filled with water. Try to keep it away from AC and heating vents.

Make sure the soil is well-drained. Let the top surface go dry between thorough waterings, but never let the soil dry completely or you’ll have a dead tree. Fertilize monthly from spring to early fall with a liquid houseplant fertilizer.

Pine Trees in Hawaii

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Hawaii has more native trees than any other state, but pines (Pinus spp.) do not make that list. Beginning in the 20th century, pine trees were introduced to the islands for lumber, but few of the species grew straight enough to make the experiment a success. But pines remain in Hawaii and have escaped cultivation, changing both the plant life above ground and, perhaps more disturbingly, the fungal communities below the soil’s surface.

Pine Comes to Hawaii

Five different types of pine trees grow in Hawaii, all introduced from North America. Some have done remarkably well in the warm climate, like slash pine (Pinus elliottii). This stately conifer was brought into the 50th state to combat erosion and for use as lumber. The tree, which grows in U.S. Department of Agriculture plant hardiness zones 7 through 11, thrives in plantations in Kauai and Molokai and occasionally escapes cultivation. It has high drought tolerance and will grow in almost any soil, including clay and mud. The U.S. Forest Service calls the tree a prolific seed producer that “seeds itself into the landscape.”

Other Successful Pines

Another tree introduced for lumber, the loblolly pine (Pinus taeda), which grows in USDA zones 6 through 9, grows rapidly in Hawaii and produces lumber for construction. It was planted and currently grows on Maui, Kauai, Molokai and Hawaii. Jelecote pine (Pinus patula), which grows in USDA zones 8 through 9, was not successful as a lumber tree. Although this pine is grown for lumber in South Africa and Swaziland, this is not the case in Hawaii, perhaps because the tree produces multiple leaders and steep branch angles in the tropical climate. However, the graceful jelecote, with its weeping branches, dark red bark and clustered cones, has been adapted as an ornamental tree in Hawaii, planted in parks, reserves and gardens.

Less Successful Immigrants

Not every pine introduced to Hawaii has thrived. The beautiful Monterey pine (Pinus radiata) can grow rapidly to 150 feet tall with a trunk diameter exceeding 4 feet. In Hawaii, these trees have been felled by sulfuric volcano fumes as well as by fungal disease and European pine adelgid. Cluster pine (Pinus pinaster) is another tall, straight pine introduced as potential lumber. Relatively slow-growing, the tree has also fallen victim to pests and diseases in Hawaii. Cluster pine regenerates profusely after fire, forming thick clumps that shade out native species. It has been nominated as one of the world’s top 100 invaders. Both species grow in USDA zones 7 through 9.

Pine Invasion

No conifer is more invasive worldwide than pine, and the threat is greatest to tropical regions without native pine trees. Pines have a symbiotic relationship with certain fungi, called ectomycorrhizal fungi, and cannot survive unless they are present in the soil. So, for pines to colonize an area that does not have a native pine population, ectomycorrhizal fungi must also be introduced. As pines find their way out of plantations to wild areas of the state, native plants and the makeup of the soil organisms are under threat. This may make restoration projects in Hawaii impossible.

During the summer months you should place the cultivation pots in a shady, well-aired room with temperatures between 18 ° C and 23 ° C. The required moisture is removed from the air, watering is not desired. The first small plants that you can winter in the house should be developed by autumn. Temperatures between 10 ° C and 12 ° C are required.

Water them as in the case of adult plants: The root ball may not dry out, but only very little is poured. As a rule, it takes about three years for a separate pine to develop after sowing to be treated as an adult conifers.

Cuttings

  • use only terminal cuttings
  • the cutting should take place in winter
  • there need to be at least one whorl of branch and a middle flower bud
  • cut more or less 4cm under the whorl of branch

Fill a nutrient-poor substrate into pots with a diameter of 9 cm. The seedling is planted so deep that the knot is directly above the ground. The substrate is moistened with lime-poor water. To maintain the moisture content, you should stretch a transparent film over the container. Keep the temperature constant at about 18 ° C to 22 ° C. The rooting should take place within 2 to 3 months. To prevent mold formation, you should ventilate the film daily.

Interfaces do not grow again. As a result, amateur gardeners tend to plant potted plants and cultivate the plants for about three years. At this time, the trailed conifers are large enough to deliver beautiful seedlings. These young seedlings develop within a few months to shapely, youthful Norfolk firs, and the elegant appearance of the firs is not disturbed.

Diseases

The only important disease, which can infect the pine in the container, is stem rot: From the shoot upwards, a brownish coloration develops, which spreads and leads to the death of the plant.

Pests

Thripse

There are bright, small suction spots, and you can find about 1mm large animals and larvae. The so-called fringe wings or bubble feet are rather inconspicuous, not least because of their small size. Thripse occur in Europe in many different ways, some of them are only viable in greenhouses.

So it may be that your conifers bring the pests already from the nursery school or the garden center, because thripse are only limited in flight, but can jump quite far. They overwinter in the ground and feed on vegetable juices.

Mealybugs

You will not see mealybugs theirselves. The animals are covered with white wax and sit on the shoots and leaves of the conifers. They hardly move, but are often polluted with the honeydew and soot dew fungus. Fighting those mealybugs is only possible with special pesticides that do not damage the plant itself.

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Norfolk Island Pine Bonsai Tree Care Guide (Araucaria heterophylla)

The Norfolk Island Pine is usually sold in nurseries and grocery stores around Christmas Time because it resembles miniature Christmas tree. Some even go as far as to attach mini ornaments and garland to the branches. The Norfolk Island pine, in its natural habitat, is quite different from these cute little trees.

The origin of the tree is in the South Pacific on a tiny little 13-square foot island between Australia and New Zealand where the tree grows about 200 feet high. Although usual bonsai techniques must be altered, the small tree can be trained into a nice bonsai that will last for several years.

Scientific/Botanical Name Araucaria heterophylla
Description The evergreen Norfolk Island pine tree is named for the island that lies eastward of Australia, in the southern Pacific Ocean. Norfolk Island pine trees grow tall and straight, and the branching is highly symmetrical. The tree is capable of reaching a height of 200 feet in the wild.
Position The tree can be grown indoors, but the plant should be rotated on a weekly basis so that the trunk gets an even exposure to its light source. Failure to rotate the plant will result in a bent trunk. Outdoors, the tree prefers full sun, but it is equally adapted to part-shade. The best outdoor cultivation occurs in USDA planting zones 10 and 11, but the tree does require protection from frigid conditions.
Watering Norfolk pine does not like the soil to be wet, but it also does not like to be totally dry: The ideal watering schedule is one that allows the plant to become just a little dry between each watering. More water will be required during the summer and, conversely, less water will be required during the wintertime.
Feeding The tree should be fed with a liquid all-purpose fertilizer, but only during the spring and the fall.
Leaf and Branch Pruning Norfolk Island pine trees are a challenge to prune, and pruning must be carried out with great care so as not to retard the growth of the plant. The best time to prune the tree is during springtime. The new buds should be pruned while they are still a light-green color.
Re-potting & Growing Medium Re-pot the tree every other year in loose, easy-draining soil. A good bonsai soil mix is recommended.
Wiring The tree can be wired throughout the year, but wires should be removed within four months of being placed.
Notes The Norfolk Island pine tree is beautifully-suited to any of the classical bonsai styling: The formal and informal upright styles are particularly stunning when used with this tree. Norfolk Island bonsai trees make wonderful tabletop Christmas trees.

Description

Norfolk Island Pines are not actually pine trees, but are conifers with whorled branches and feathery needle-like leaves. The limbs grow in tiers on the thin trunk with five to seven branches in each tier. The sharp little bright green leaves are around ½ inch long and curve slightly.

Height varies from about 1 foot to 10 feet high when used as an indoor plant. The branches, in their natural state, droop gracefully down in an elegant manner.

The scientific name for the tree is Araucaria heterophylla and its growth is relatively slow at 3 to 6 inches a year making it a good candidate for a bonsai.

Light And Temperature Requirements

The Norfolk Island Pine makes a charming and lush houseplant. Basic requirements include about two to three hours direct sunlight on a daily basis and regular watering. The trunk may grow toward the light making it essential to turn the plant a quarter turn every week so it does not curve.

The tree does not tolerate cold temperatures and should never be exposed to any temperatures below 50 degrees Fahrenheit. It also does not appreciate extremely hot temperatures. It prefers daytime temperatures of about 65 to 70 degrees and nighttime temperatures at about 60 degrees.

The tree can survive outside during the summer as long as temperatures are moderate and they are not placed in a windy area that can dry the tree out and cause breakage. The origin of the tree is unusual in that temperatures on the island do not change much but stay about 70 degrees at all times.

Containers, Potting And Repotting

The roots of a new Norfolk Island Pine are usually very short and shallow and some may not have much root at all. Plant them in a 6 inch pot at first. This allows the roots to expand enough for the plant to grow about 2 feet tall. If a taller plant is desired, wait a few years and repot the tree in an 8 inch pot to allow it to grow another full foot.

A Norfolk Island Pine that graduates to a 24 inch pot will probably grow 12 feet tall and be a little too big to be considered a bonsai. Pots do not have to be tall and can be rather shallow, but should be heavy enough to counterweight the height of the tree so that it will not fall over. Plants should be repotted about every two to four years.

The Norfolk Island Pine does not appreciate root cutting to keep the plant small, as in bonsai culture, because the roots are insignificant to begin with.

Soil

Use a commercial houseplant mix in which to plant the Norfolk Island Pine. Make sure there is enough drainage so that any excess water will drain away from the soil. Placing a one inch or more layer of pebbles under the soil mix will make for efficient drainage and will also add weight to the pot.

Water

Norfolk Island Pines prefer even moisture but do not like soggy soil. Let the top 1 inch of the soil dry out between watering times. Check the plant every two to three days as shallow pots do tend to dry out quickly. The best way to water is to place the pot in a sink and apply water until it starts to drain out the bottom.

Put the plant back in its place when thoroughly drained. If moving the plant is not possible water as usual and empty any excess water in the drain saucer by tipping or using a turkey baster. Tap water is acceptable to use, but let it sit out about an hour before watering so the water is room temperature and some of the chlorine has dissipated.

Humidity

Norfolk Island Pines will dry up and die without proper humidity of about 50 percent. Run a humidifier in the winter or place the pot over a saucer filled with pebbles. Keep water in the saucer that reaches just below the pebbles and when it dries out, add more water.

Fertilization

Norfolk Island Pines do need periodic fertilization especially when being kept as a bonsai. They need fertilization only during the growing period from spring through summer. Never fertilize in the winter dormant months and avoid fertilization 3 to 4 weeks after being potted or repotted.

Use a water-soluble fertilizer for foliage houseplants. A good combination fertilizer is one with the numbers 20-20-20. Use per the package instructions fertilizing every month starting in April or May and continuing until September.

Bonsai Techniques

Regular bonsai, like umbrella trees or ficus, are usually trained by wrapping wire around the branches in order to hold them in place. Eventually the branches will stay in the desired shape and wire is removed. Foliage and trunks are trimmed in order to give the tree an old and gnarled look.

Norfolk Island Pines do not particularly adhere to this type of training because of the nature of the plant. Trunks are relatively thin, often the size of a pencil or thinner, when first planted and even when they grow 200 feet the trunk only grows to 10 feet wide.

The branches are very flexible and feathery and do not usually conform to wire training no matter how long the wire is maintained. Eventually the bottom branches will dry, die, need to be removed and will not grow back. This gives the tree a rather palm-like appearance or a trunk with a pom-pom on top.

Cutting the trunk or most of the foliage usually results in death. Sometimes, when the trunk is cut to encourage alternate growth, it will come back, but it takes quite a long time.

It is best to let the tree grow in its natural shape and allow it to grow slowly in order to make it a bonsai. Another method is to cluster it with several other small Norfolk Island Pines to make forest-like growth in a pot.

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