Why Does My Pine Have Brown Needles?

Does your pine grow along the road and are only the needles facing the road brown?

Are the needles brown at the tip of the needle while the base of the needle remains green?

Do the needles have small, yellow-to-brown, resin-soaked spots throughout the summer; within the spots, tiny black bumps pushing through the surface can be seen?

Are there any raised, black, football-shaped fruiting bodies on dead needles still attached to the tree and those on the ground?

Do the branches have small holes with sawdust material coming out of them?

Have your pine tree gone through a harsh winter or late frost?

Conifers located along the road can be damaged by road salt. Road crews often apply sodium chloride during winter to keep roads clear. Many plants, especially eastern white pine, are sensitive to salt spray from roadways. Acute damage caused by direct salt exposure is easy to spot since the damage is usually greatest on the side of the trees facing the road. Sensitive trees such as white pine can usually survive one-year’s damage but repeated acute damage can ultimately disfigure or kill trees.

Dothistroma needle blight is a fungal disease caused by the fungus Mycosphaerella pini. Austrian pine trees are the most common variety attacked by Dothistroma needle blight. Dothistroma spores spread by wind and rain and can infect needles throughout the growing season. Protect new needles by applying copper-based fungicides just as the new needles emerge from the needle sheaths and as the spores are released from the fruiting bodies.

Brown spot needle blight is a fungal disease caused by the fungus Mycosphaerella dearnessii. Short-needled Scots pine varieties such as Spanish and French-green are more susceptible to fungal attack than the long-needled varieties. Brown spots can be controlled by fungicidal sprays. The first application should be applied when the new needles are about half-grown (May-June), and a second spray three to four weeks later.

Lophodermium is a severe needle cast of Scots pine, which in some cases can cause the entire tree to brown in spring. The most important time to protect trees is from the end of July through September. This is when needles are infected from spores being released by the small, shiny, football-shaped, black fruiting bodies that form on the fallen needles. To break this disease cycle, the time to manage this disease with a fungicide is particularly in late July and throughout August.

Bark beetles are insects that tunnel into trees to lay their eggs. Some species may spend most of their lives inside the tree. The damage is caused by a combination of bark beetle tunneling activities and the nematodes that ride along with them into the heart of pine trees. If you’re seeing symptoms and signs of bark beetles, it’s too late to save your pine. Your tree needs to be removed.

Many conifers are subject to needle drying of frost burn during the winter. The most common symptom of frost burn is brown or red foliage on the exposed side of the tree. In some cases, trees will have a snowline below which no damage occurs since those needles were under snow when the rest of the tree was drying. Winter burn occurs frequently on dwarf Alberta spruce but can occur on other conifers as well.

In years of heavy rain or extreme drought, pine trees may brown in response. Browning is often caused by an inability of the pine tree to uptake enough water to keep its needles alive. When moisture is overly abundant and drainage is poor, root rot is often the culprit.