Gardening Page

 An island holiday year round

 Heather Kirk-Ballard

LSU AgCenter Horticulturist

   It can stay pretty warm here in Louisiana during the winter months, and with temperatures in the upper 80s this whole week, it can feel like island time while the rest of the country experiences cooler temperatures. 

   However, we are fortunate to live in a climate where subtropical and tropical plants can grow. Our growing season is extended, and we can enjoy a diversity of plants. One such plant, the Norfolk Island pine, has become a popular holiday staple and is commonly seen and sold this time of year.

   Norfolk Island pines (Araucaria heterophylla) are not truly a pine. They are a tropical, evergreen conifer that resemble the shape of traditional pines. They are named after the island where they were discovered. Norfolk Island is an external territory of Australia in the Pacific Ocean. 

   Explorer Captain James Hook first noted and reported back about the trees from his voyage to the South Pacific in 1774. He took notice of the tall, straight trees and thought they might be useful as masts and yards for sailing ships. 

   The island was later occupied by convicts transported from Britain, and it was at that time they determined the trees were not resilient enough for nautical uses and abandoned the idea. It is, however, useful as an indoor houseplant and as a landscape tree for USDA hardiness zones 10 to 11. 

   The symmetrical shape of the tree make it especially attractive as a potted holiday tree for decorating. Trees are very slow growing. Grown outdoors in tropical, coastal locations such as California, Florida and Hawaii, the trees can grow up to 200 feet in height and up to 25 feet wide. Indoors, they can grow 3 to 8 feet in height by 3 to 4 feet wide. 

   Plants prefer full to partial sun in moist, porous, sandy, acidic soil. They can tolerate extended periods indoors with lower light but should be moved outdoors when temperatures are favorable to increase growth and prevent them from stretching and becoming leggy. 

   When grown indoors, plant soils should be allowed to dry between waterings. Once a week or every two weeks should provide enough water. Make sure there is proper drainage of the pots to allow excess water to drain. Trees prefer warm climates between 65 and 70 degrees Fahrenheit with at least 50% humidity. They cannot tolerate temperatures below 35 degrees. 

   You can mist plants with a spray bottle or leave out saucers of water to increase the humidity. Fertilizing indoor plants is recommended at low rates when new growth flushes are observed. Remove dead and diseased branches from trees grown outdoors, and no other routine pruning is necessary. Plants have some common pests such as aphids, mealybugs, mites, scale and whiteflies. Treat with organic options if needed. Overwatering can lead to fungal diseases, so allow the soil to dry between waterings. 

   Large numbers of the plant are grown and produced in South Florida for the tropical houseplant industry annually. Plants are sold in retail garden centers, florist shops and even grocery stores. You will notice that containers usually have several potted saplings grown in clumps to give pots a fuller look. Small saplings look rather wimpy as single plants. 

   The soft, compact needles and strong, widely spaced branches lend to its symmetrical shape and triangular outline, making it an ideal living Christmas or holiday tree that can be decorated with lights, ribbons and ornaments. Don’t discard the tree after the season. Keep in the container and bump up the size of pot every year or every other year to allow the tree to grow larger. They perform well on patios and should be brought indoors during extended, freezing temperatures. They can be planted outdoors in protected areas that have favorable temperatures year round. ∆