Diplodia Tip Blight Treatment by SavATree Insects & Diseases Diplodia tip blight (Diplodia pinea) is a serious fungal disease that weakens tree vitality over time, leading to aesthetic damage, growth reduction, and, in severe cases, structural decline. The disease is commonly seen in urban and suburban landscapes, particularly where trees are under environmental stress. While young trees are typically more resistant due to less cone production and more vigorous growth, older, cone-bearing pines are highly susceptible. Diplodia tip blight primarily affects two-needle pine species, with Austrian pine being the most commonly and severely impacted in landscapes. Other susceptible species include Ponderosa pine, Scots pine, and Mugo pine. While these are the most frequent hosts, other conifers may also be affected, particularly when growing under stressful environmental conditions. Signs of Diplodia Tip Blight Early detection is essential for controlling the spread of Diplodia tip blight and preserving tree health. Common signs to look for include: Stunted or dead shoots, particularly of the current year’s growth New shoots that are brown or deformed Visible resin on infected twigs, often drying into a white crust Black fungal pustules (pycnidia) at the base of needle pairs under the bundle sheath Needle death beginning on lower branches and moving upward Resinous, sunken cankers or stained sapwood under bark on infected branches Where and When to Look for Diplodia Tip Blight Diplodia tip blight is especially prevalent in stressed trees located in the Northeastern, Midwestern, and Mid-Atlantic regions, as well as parts of the Southeast and Pacific Northwest. Urban landscapes, where trees face greater environmental stress, are often hotspots for infection. The highest risk of infection occurs in spring, particularly May to early June, during a brief but critical window when new buds begin to break from their sheaths. Cool, wet conditions at this time can accelerate infection, but even minimal spring rain can allow the fungus to infect developing shoots. A secondary spore release may occur in late summer, although spring remains the primary infection period. How Diplodia Tip Blight Harms Your Trees Diplodia tip blight infects pine trees in the spring, just as new shoots (also called candles) begin to grow. The fungus produces spores on infected cones, which are spread downward by rain. When these spores reach the developing shoots, they infect the tissue and begin to spread internally, disrupting the tree’s ability to move water and nutrients. As a result, the tips dieback or become stunted, producing short, brown, or deformed growth. Beyond shoot dieback, infected twigs often exude resin, which dries into a white crust. In more advanced infections, trees may develop sunken cankers on branches or stems, and the wood underneath the bark may become stained or discolored. These symptoms weaken tree structure and appearance over time. While the disease progresses slowly, repeated infections from year to year reduce overall vigor and canopy density. Affected trees may appear healthy some seasons, but long-term damage accumulates. Eventually, trees that are already stressed may decline beyond recovery, especially if impacted by drought or secondary pests like bark beetles. How to Prevent Diplodia Tip Blight Although trees infected with Diplodia tip blight can be treated, it is a chronic disease with no curative treatment, making prevention the best defense. Proactive care is the most effective way to protect your trees and reduce the risk of long-term damage. To prevent Diplodia tip blight it is important to maintain strong overall tree health. This includes cultural practices such as pruning dead or dying branches during dry weather, avoiding overwatering, and improving airflow around trees by thinning surrounding vegetation. It’s also important to monitor soil conditions—compacted or nutrient-poor soils can stress trees and increase their susceptibility to infection. Keeping trees healthy through proper watering and routine care goes a long way in minimizing disease pressure. SavATree’s ISA certified arborists can offer professional guidance, assist in proper tree care maintenance, and offer specific treatment plans to help prevent diseases like Diplodia tip blight. Where to Find Diplodia Tip Blight Treatment Near You Diplodia tip blight can be difficult to control without expert support. SavATree offers a series of targeted applications beginning at or just before bud break in the spring. Because timing is critical, early-season treatments offer the best protection. To support root health and help trees recover from stress, ArborKelp® may be applied to improve nutrient uptake, moisture retention, and overall resilience. For enhanced spring recovery, ArborHealth® Plus Kelp is often recommended to promote stronger, more disease-resistant shoot growth. At SavATree, our ISA Certified Arborists offer site-specific care plans tailored to your region, tree species, and landscape needs. We also offer comprehensive disease treatments to address existing infections and prevent future outbreaks. With consistent care and professional support, the effects of Diplodia tip blight can be minimized, protecting the health, appearance, and longevity of your trees. Contact us today to schedule a consultation with an expert arborist.