I cut down the lower brown branch of my Norfolk Island pine tree about 6-8 months ago. I think it didn’t heal properly. Now there is a lot of greeze rubber like liquid coming out from that point and when I cleaned it up the inner stem was visible which was red. The viscous liquid is still coming out. The plant seems to be okay but im worried.
Thank you for contacting Toronto Master Gardeners. Araucaria heterophylla, commonly called Norfolk Island Pine are great sculptural trees to enhance a sunny spot in the home, especially during the winter holiday season. Araucaria heterophylla are endemic to Norfolk Island (a territory of Australia). They are grown outdoors as ornamental trees in Mediterranean climates and can grow as high as 50 – 60 meters tall. In our climate, they are frequently grown as house plants.
The thick, sticky liquid oozing from your plant is sap. Sap consists of water, sugars and other nutrients. Tree sap is constantly circulating in plants to bring the essentials for growth up from the roots and down from the leaves. Damage to a branch, including pruning off a dead branch, is the primary cause of leaking sap in trees. This is a normal response, no different than when you bleed due to a cut. If possible, it’s best to leave the sap where the tree is injured as it will help in the healing process.
If your tree has been outside for the summer months, there is the possibility that the wound leaking sap is diseased with a fungi or it could have been invaded by a borer insect. As the rest of your tree seems to be doing well, I suspect the sap you’re seeing is just a normal healing response to being pruned. Below are two additional answers to previous questions about Norfolk Island Pine care that may be helpful. The key to keeping these trees healthy is adequate direct sunlight, adequate moisture and good humidity.