Two-needled pines can offer privacy and protection to your landscape, but in stressful environments can become infected with a fungal disease called Diplodia Tip Blight.
When are my trees at risk and what should I look for?
Diplodia tip blight is a fungal disease of Austrian, Scots, mugo, red and other two-needled pines. This disease does not typically kill the tree, but over time brown shoot tips occur and can cause entire branches to die. Trees in more stressful situations may be more seriously affected.
This fungus overwinters on infected needles, cone scales, or the bark of infected twigs. In the spring through late fall, spores are released from the overwintering lesions. The fungus is more likely to spread during this time due to splashing rain or irrigation water.
Early symptoms of Diplodia include yellowing and stunting on the tips of the lowermost branches of the infected trees. These symptoms typically are noticeable from mid-summer into fall. Pathogens build up on the cones before spreading to infect the shoot tip, so trees of non-cone bearing age do not have symptoms. This fungus overwinters and spreads from diseased cones. Lower branches are more susceptible to the disease because they are closer to the old diseased cones that have fallen to the ground and lay beneath the tree.
Diplodia usually cannot be cured, but there are many methods to prevent this disease from affecting your pines. Your local arborist will develop a prevention plan that will be the most effective for your unique property. Find your local arborist here or view the full PDF.