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 holiday staple and is commonly seen and sold at this time of year.
Norfolk Island pines (Araucaria heterophylla) are not really pines. It is an evergreen tropical conifer that resembles 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 Cook first noted and reported the trees from his voyage to the South Pacific in 1774. He noticed 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 then that they determined that the trees were not strong 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 through 11.
The symmetrical shape of the tree makes it particularly attractive as a potted holiday tree for decoration. Trees grow very slowly. Grown outdoors in tropical coastal regions such as California, Florida, and Hawaii, the trees can grow up to 200 feet tall and up to 25 feet wide. Indoors, they can reach 3 to 8 feet tall by 3 to 4 feet wide.
Plants prefer full to partial sun in moist, porous, sandy, acidic soil. They can tolerate long periods indoors with lower light, but should be moved outdoors when temperatures are favorable to increase growth and prevent them from stretching and getting long.
When grown indoors, the plants’ soils should be allowed to dry out between waterings. Once a week or every two weeks should provide enough water. Make sure there is good drainage from the pots to allow excess water to drain away. The trees prefer warm climates between 65 F and 70 F with at least 50% humidity. They cannot tolerate temperatures below 35 F.
You can mist the plants with a spray bottle or leave saucers of water to increase the humidity. Fertilization of indoor plants is recommended at low rates when new growth spurts are observed. Remove dead and diseased branches from trees grown outdoors, and no other routine pruning is needed. Plants have common pests such as aphids, scale insects, spider mites, scale insects and whiteflies. Treat with organic options if needed. Overwatering can lead to fungal diseases, so let the soil dry out between waterings.
A large number of plants are grown and produced each year in South Florida for the tropical houseplant industry. Plants are sold at retail garden centers, florists, and even grocery stores. You will notice that containers usually have several potted plants grown in clumps to give the pots a fuller look. Small trees look rather weak as single plants.
The soft, compact needles and strong, widely spaced branches lend themselves to its symmetrical shape and triangular outline, making it an ideal Christmas or holiday tree that can be decorated with lights, ribbons and ornaments. Do not discard the tree after the season. Keep in the container and increase the size of the pot every year or two to allow the tree to get bigger. They work well on patios and need to be brought indoors during prolonged, freezing temperatures. They can be planted outdoors in protected areas that have favorable temperatures all year round.