Pine trees release sap naturally or in response to pruning, wounding or attack by insects or disease. The leakage of sap is often a normal biological process of the trees and is not always a sign of a problem. The most important step when such symptoms arise is to identify the cause. If pruning has not recently occurred, insect or disease may be to blame. Whatever the cause, proper environmental conditions are crucial for the tree to stay healthy under such stresses.
Identify the cause of the leaking sap problem. Multiple sites of leakage are a sign that the problem is not from wounding. Bark beetles are a serious infestation and can be identified by the presence of sawdust, small holes in bark, leaking sap from bark and dying needles. Canker diseases cause white patches of dry resin.
Spray the tree with insecticide if insect attack is suspected. Pine trees release resin as a defense response to boring insects. Pine bark beetles are a common issue across North America, causing leaking sap and dying foliage. The red turpentine beetle may also cause these symptoms.
Seal wounds, if they are present, in order to prevent disease or insects from entering the wounds. Many tree wound sealants are available at home and garden centers. If the pine tree is leaking sap due to recent pruning, patching is not necessary. The loss of some sap will not harm the tree.
Remove branches that appear diseased or infected with pruning shears if a fungal infection is suspected. Determine if cytospora canker may be present in the tree. This disease effects the white pine and causes white sap to flow from cankers. The dry resin appears in white patches and needles turn brown and drop in winter. Prune infected branches and provide optimum care to prevent the spread of this disease.
Change your pruning schedule if you believe pruning is to blame for the leaking sap. Prune early in the year after new growth is appearing at branch tips, and remove just 1/3 of the growth each year.