Late this summer, the top vertical stem of our white pine turned brown and died. The balance of the tree remained healthy. In the fall, the brown began moving down the tree. This tree is about 7 years old and sits at the edge of our woods. It has eastern exposure with acidic soil. I am not sure if the sprinkler system hits it. When we first saw the top stem turning brown, we watered the tree several times with a Miracid. Earlier in the summer, we lost a white pine that started with these same symptoms. Is there anything we can do to save this tree?

Seeking the services of a certified arborist will be your best defense against losing your tree because it is exhibiting symptoms that can be caused by more than one problem. An insect, the white pine weevil, bores into the terminal shoot causing death of that branch. The weevil rarely kills the whole tree, but places it in a weakened state where the attack of other insects, diseases, or environmental problems can cause gradual death.

Eastern white pine (Pinus strobus) is a fast-growing tree. Unfortunately, as they mature, many develop problems. The symptoms reported are a general off-color, yellowing or browning of the needles, stunted growth, stunted needles, or total browning of the tree followed by death. The cause for the decline is most often due to environmental stresses rather than a particular pest. The stress opens the door to secondary attacks by diseases and insects, which then accelerate the decline of the tree. Stress is the primary problem because it weakens the tree’s natural resistance.

Location of a white pine tree is very important for proper health and vigor. White pines require well-drained, deep, fertile, acidic soil with a moderate amount of moisture. They do not tolerate poorly-drained soil, high pH, compacted soil, a thin topsoil layer, buried debris or drought. Any other conditions that restrict root growth are also detrimental to white pine trees. Root diseases and cankers are the most common fungal pathogens that attack the Eastern white pine. Root disease symptoms are characterized by overall poor growth, the tree becomes off-color, wilts and dies.

Insects often act as vectors (transporters of the pathogen) for diseases. They breed in the dead trees and stumps. Then the new generations move to the surrounding stressed trees, bringing the disease with them. Other attackers of stressed white pine include the pinewood nematode, which feeds on vascular tissue in the branches and trunks of all pines and some other conifers. An insect called the pine sawyer beetle acts as a vector for the nematode, introducing it to healthy trees. Damage from the pinewood nematode is seen as sudden wilting and death.

When Eastern white pine trees decline they should be removed quickly so they do not act as breeding places for insects that spread diseases to surrounding trees. Replace dead trees with other evergreens that can better tolerate the existing site conditions.

I have a large tulip tree; the roots of this tree were damaged during a fence installation. Subsequently the tree developed slime flux and many branches died. I have kept the tree well-watered and fertilized, and it appears to be recovering and making much new growth. When would be the proper time to remove the dead branches from the tree? They are unsightly and some are quite large and could damage structures if they fell.

The tulip tree (Liriodendron tulipifera) is not a tree for residential property. Many times we as gardeners just cannot help ourselves and purchase or inherit a tree that struggles where it is planted. The tulip tree needs a large, open area to grow and develop its branches and root system to display its real beauty and remain healthy.

You are taking the correct steps to insure the health and longevity of your tree after its injury. Since there are no curative or preventive measures for slime flux, you are correct in practicing IPM (Integrated Pest Management) to maintain the tree in a state of vigor by using a consistent watering and fertilization program and minimizing future wounds or injuries.

The best time to prune off the dead limbs would be in the tree’s dormant season, leaving less chance to spread the disease. When pruning, use a 20 percent bleach solution in water to dip and wipe your tools when changing cutting areas. This procedure will stop the spread of the disease from infected tools to healthy tree tissue.

Lastly, please investigate all the symptoms of slime flux to confirm your diagnosis, as this bacterial disease does not usually affect tulip trees in our area. Other diseases and insects are more likely to cause a problem showing some of the same symptoms, like aphids, which secrete large quantities of “honeydew” (a clear sticky substance). Unlike slime flux, however, there is a treatment program for aphids.