Declining trees tend to be in sites with several or all of the following characteristics: High soil pH. Check out this list to identify your pine tree’s symptoms and find suggested treatments. But there are easier, less radical solutions to other problems. Drought-like conditions are another cause of arborvitae turning brown. Pine trees are evergreen, so you don’t expect to see dead, brown needles. Both of those issues can cause your arborvitae to turn brown. Drought weighs heavily on trees like the arborvitae, and watering during this season is essential. Tree browning and death follow. Brown spot needle blight causes needle spots, browning and needle loss on pine trees. Needles over … Look for sunken infection sites on the tree trunk. Needles are shorter than normal, needle tips turn brown, and the overall tree canopy becomes sparse. Infected trees have slow growth and often have bare lower branches. In the summertime, your tree is likely combating intense heat from the sun, as well as dry soil. The most common cause of brown pine needles occurs in the fall and is normal. Pines shed older needles similarly to other trees’ fall foliage drop. If you find dead needles on lower pine branches only, you are probably not looking at normal needle shed. Symptoms: Between March and April, the needles on the lower part of the tree begin to turn brown. Pine Trees Affected: This disease causes the most damage to Austrian pine and Ponderosa pine. It you see dead needles on pine trees, take the time to figure out the cause. The Southern pine beetle, for example, is a highly destructive pest that affects pines in the Southern U.S., and often the only “cure” is to remove the infested trees. Start by noting the season and which part of the tree is affected. The disease can eventually kill young trees … … Red, mugo, and Scotch pines are also susceptible. Several factors related to growing conditions are involved in white pine decline. Note yellowing needles that brown and fall and follow down their branches to look for lesions. Ponderosa and Scots pines are severely damaged by this disease in Minnesota. Drought.