Pine tree problem - Ask Extension
My neighbor and I have found a problem in our pine trees. They have brown sections. Could this be due to drought? disease? We do not use chemicals alt...
Knowledgebase
Pine tree problem #854885
Asked November 07, 2023, 3:54 PM EST
My neighbor and I have found a problem in our pine trees. They have brown sections. Could this be due to drought? disease? We do not use chemicals although some other neighbors do
Could you give us some help in identifying what's going on? Thanks
Baltimore County Maryland
Expert Response
The tree is a spruce (not pine...they can get some of the same issues, but don't overlap completely), and some of the needle yellowing looks normal for this time of year. Even though they keep leaves in the winter, evergreens do still shed some foliage each year; it will be the older leaves behind the tip growth on the branches.
Spruces are also vulnerable to at least two needle cast diseases, though we see this most often on Colorado Blue Spruce. (Your tree looks like a Norway Spruce.) Despite their continued popularity in landscaping in our area, spruce trees are not well-adapted to our hot, humid summers and clay-based soil. We can't tell if some of the yellowing pictured is due to fungal infection, insect pests (scale being a candidate, though we don't see any), or not, but there is little that could be done if it was, especially if you prefer to avoid pesticides. Shade on the tree's branches will also exacerbate needle loss, as spruces prefer full sun (6+ hours of direct sun in summer).
For any tree surrounded by turfgrass, we recommend that the trunk base and at least part of the root zone be covered in mulch to keep the grass from growing too close to the trunk. This reduces root competition for resources but also helps avoid damage to the trunk from mowers and weed-whacking; if too many cuts damage the bark, it can be fatal to the tree as there is no treatment.
Drought could be playing a role in exacerbated needle shed as well; many areas of Maryland experienced drought this year (some still are). Monitoring the tree for watering needs can help avoid tree stress going forward. Spruces do not replace needles that are shed, regardless of the reason. New growth will continue to grow on branch tips as long as the tree is healthy. Any branches that become fully bare can be pruned off since they will not regrow.
Miri
Spruces are also vulnerable to at least two needle cast diseases, though we see this most often on Colorado Blue Spruce. (Your tree looks like a Norway Spruce.) Despite their continued popularity in landscaping in our area, spruce trees are not well-adapted to our hot, humid summers and clay-based soil. We can't tell if some of the yellowing pictured is due to fungal infection, insect pests (scale being a candidate, though we don't see any), or not, but there is little that could be done if it was, especially if you prefer to avoid pesticides. Shade on the tree's branches will also exacerbate needle loss, as spruces prefer full sun (6+ hours of direct sun in summer).
For any tree surrounded by turfgrass, we recommend that the trunk base and at least part of the root zone be covered in mulch to keep the grass from growing too close to the trunk. This reduces root competition for resources but also helps avoid damage to the trunk from mowers and weed-whacking; if too many cuts damage the bark, it can be fatal to the tree as there is no treatment.
Drought could be playing a role in exacerbated needle shed as well; many areas of Maryland experienced drought this year (some still are). Monitoring the tree for watering needs can help avoid tree stress going forward. Spruces do not replace needles that are shed, regardless of the reason. New growth will continue to grow on branch tips as long as the tree is healthy. Any branches that become fully bare can be pruned off since they will not regrow.
Miri
