McLain | Norfolk pine comes for Christmas, stays all year

With Christmas 2011 past history, trees we purchased from Christmas tree lots have long been discarded. Artificial ones have been stored away until next year. Those who purchased live trees have either already planted them outdoors or have stored them in a sheltered place until they can be planted next spring.

But there is a small minority of Christmas tree owners who have simply removed the decorations from their trees and they will continue to enjoy them as attractive houseplants until it's time to decorate them again next Christmas.

How can that be? You can't keep a live Christmas tree in your home year-round, can you? In fact you can -- if you use a live Norfolk Island pine.

Norfolk Island pines in pots have long been in the horticulture trade. However, it has been one of the best kept secrets that they also make exceptional Christmas trees.

History of Norfolk pines

Norfolk Island pines are one of the few conifer trees indigenous to the Southern Hemisphere. They are native of Norfolk Island, which is just a tiny speck in the South Pacific Ocean, and is about 900 miles east of Brisbane, Australia. Just a few thousand people live on this semitropical island that was formed many eons ago by volcanic activity.

At one time huge 200-foot tall Norfolk Island pines were in high demand for building wooden seafaring ships. But today it's the export of miniature potted Norfolk pines that makes this tree a welcome worldwide household plant -- and a great little Christmas tree.

Why ideal?

You needn't worry that your potted Norfolk Island will grow up though your roof. Those planted in 6-inch pots will grow to be no more than 2 feet tall before they permanently stop growing. Transplanted into 8-inch pots, they will reach 3 feet tall, and those moved to 10-inch pots will top out at 4 feet and 5 feet, mainly because Norfolk Island pines, which aren't true pines, have weak root systems.

They are often available in nurseries and in big box stores before the Christmas season and during most of the year. By searching the Internet you can purchase these beautiful miniature trees year-round.

Leading up to Christmas these little beauties are quite often available decorated with red bows and other small adornments. They make great tabletop Christmas trees that are perfect for apartment dwellers and others who want a tree that takes up little space.

Challenges of growing

These miniature trees thrive best indoors when they receive at least two or three hours of direct sunlight daily. For the rest of the day they do very well with bright, indirect sunlight. With more shade their needles tend to droop, but many owners consider this a plus as they believe it adds to their beauty.

Watering is not much of a problem if you monitor the soil moisture frequently. When the top inch of the soil is dry to the touch it's time to water. The best method is to set the pot in the sink and water with lukewarm water until it drains freely from the bottom of the pot. After it has stop draining, return the pot to its saucer. But under no circumstance let the pot remain in a saucer filled with water. Root rot then becomes problematic.

Norfolk island pines prefer indoors temperatures between 55 and 75 degrees. But if you keep your thermostat set at 70 degrees or higher at night, your tree will have a problem since it likes cool nights. Don't take your tree outside in late spring or early summer until night temperatures consistently remain above 50 degrees. Should the temperature drop below 40 degrees you can count on your tree being severely damaged or killed.

Placing your Norfolk Island pine outdoors where it receives direct sunlight most of the day is not a good idea. Doing so will likely lead to a bad case of foliage sunburn. In late summer or early fall, before you bring your tree back indoors, slowly acclimate it to the indoors by increasing its shade slowly. Brought inside without acclimating it can lead to needle drop. Unfortunately, these needles will not be replaced.

Fertilize monthly from March to September with a balanced fertilizer when it is actively growing. Houseplant fertilizer will work just fine.

The biggest challenge of caring for your Norfolk Island pine is meeting its humidity requirements. They thrive when the humidity is similar to that of their homeland, which is about 50 percent. But the humidity of most of our homes isn't even half that high. You will definitely need to raise the humidity around your tree.

One way to accomplish this is to group all your houseplants close together. All plants transpire moisture from their leaves. When grouped close together, this will raise the humidity around all of them.

Another way to raise the humidity around your Norfolk Island pine is to set its pot on a deep saucer filled with pebbles that is kept partially filled with water. Evaporation of the water will boost the humidity somewhat. But be sure that the water level in the saucer doesn't come in contact with the bottom of the pot so that water is wicked up into the pot. This can cause root rot and ultimately the death of your tree.

The best solution to increase humidity is by using a humidifier. If you are fortunate enough to have a humidifier built into your heating and air conditioning system, the humidity problem is practically solved. All you need to do is set the humidity close to that needed by your Norfolk Island pine. A more inexpensive alternative is to use a small humidifier purchased from the drugstore that is commonly used to relieve chest congestion.

One last tip: Turn your Norfolk Island pine a quarter way around each week when is actively growing. Otherwise, the side left facing the sun will grow faster than the other sides, which will ruin the symmetry of this gorgeous houseplant and cute little Christmas tree.

* Freelance gardening columnist Jim McLain can be reached at 509-697-6112 or ongardening@fairpoint.net.