Consider this situation: You notice that the Scotch pine in your landscape looks like it is dying. The new growth from last year has turned brown and is dead. Also, there are holes in the trunk of the tree that are exuding sap, which is running down the trunk. On closer inspection, you notice that there are two different types of holes. One set of holes are neatly arranged in a horizontal line around the circumference of the trunk with the holes about 1.5 – 2 inches apart. You find several of these holes in the middle third of the tree’s trunk. These are the holes exuding sap. The other type of hole, on the other hand, appears to be random and is predominantly confined to the top third of the tree. There is no sap coming from this type of hole.

What could have caused all this damage?
What made all those holes and killed the growth from last year? There are actually three offenders:
The Bird: The neat arrangement of holes around the trunk was caused by a bird called the Yellow Bellied Sapsucker. The damage they cause rarely results in the death of a tree, but the sap is unsightly. It is possible to scrape it off without damaging the tree.
The Bug: The other holes that appear to be random are the exit holes of any number of different types of wood boring beetles. Identification is somewhat difficult as the culprit has flown away. However, measuring the diameter and the depth of the hole will help in the identification process. Identifying the insect will reveal its life cycle and the optimum time for control. You may have to use the services of a professional tree service.
The Fungus: Identifying what caused the death of last years' growth is somewhat easier. If there is an absence of any other physical damage, the cause was most likely due to a fungus. Diplodia is one type of fungus that attacks new growth on pine trees and causes a condition called “Tip Blight.” Pine trees are more susceptible to Diplodia if they are growing under drought conditions, suffering from poor nutrition (bad soil), or planted in a site that is too shady or cramped... so keep your pines properly hydrated, reasonably sunned, and make sure their roots have plenty of room to spread out. For those pines already affected by Tip Blight, there is good news and bad news: while this condition doesn’t go away, it is reasonably easy to control with a yearly spray program - but timing is critical. The new growth on pine trees (called candles) goes through three distinct stages of development, and the tree has to be sprayed at each development stage to ensure good coverage of the new growth. Stage one is the lengthening of the candle. Stage two is when the needles have emerged and are halfway developed. Stage three is full development of the needles. Here again, you might be best served to employ a professional tree service.
The Takeaway:
Trees and shrubs are constantly under attack from pests and diseases, and controlling them can be difficult. Identification of the disease or the insect is essential, otherwise control attempts may end up in failure. Identify what you can (Google is your best friend), take pictures if you need to, and if all else fails - make friends with your local tree service. Good luck to you, and the pines you love.
Commentaires