problem with pine - Ask Extension
The pinus in our front yard developed rust colored needles in the fall. I thought I would wait until spring to see if it recovered, but it appears the...
Knowledgebase
problem with pine #819327
Asked January 27, 2023, 3:03 PM EST
The pinus in our front yard developed rust colored needles in the fall. I thought I would wait until spring to see if it recovered, but it appears the same thing is happening to two neighboring tree/bushes to varying degrees. Can you tell me what this is and how I should deal with it? The third picture is of one of the trees near the first. Thank you very much for your help
Montgomery County Maryland
Expert Response
Unfortunately when evergreens like pine turn completely brown they do not recover. (Some yellowing, browning, and shedding of their older, inner needles every year is normal, but the browning won't extend to the branch tips on healthy growth.) As to what caused this, it's hard to say so long after it began, and we don't see any clear details pointing to a particular cause in the photos.
Pines are sensitive to poor soil drainage as well as drought, so perhaps the roots stayed too wet or dry at some point prior to the browning. Frustratingly, evergreens sometimes take weeks or longer to manifest symptoms of a problem, so tracking it back to a single event can be difficult. Although a handful of insect pests and fungal diseases can attack pine, they typically do so once the plant is already under stress, even if that stress isn't yet obvious. Plus, their impacts on the tree tend not to be terribly sudden in terms of needle death, with the exception of root rot due to soil conditions.
If multiple plants in that area of the yard have succumbed, that suggests something in the site conditions isn't suitable for them, such as the aforementioned soil moisture level or perhaps heavy soil compaction. You can try replanting new trees in spring if you prefer, in case this was a fluke, or switch to a different evergreen depending on what you might suspect the issue was. For example, if you know the soil stayed wet for awhile after rain, American Holly can be a good candidate. If too dry or you aren't able to irrigate during drought, then Juniper might work better. The majority of evergreens need full sun to thrive (6 to 8 or more hours of direct light in summer) though hollies are excellent for tolerance of moderate shade. A lack of enough summer sun wouldn't be responsible for this particular dieback in the short term, but over time it's a factor to keep in mind if considering a replacement.
Lastly, if these were relatively new plants which came from the same source, maybe their root systems were in poor condition upon planting and it took this long for them to decline to the point of dieback. Sometimes nursery-grown trees become quite rootbound before they are sold, or their roots get tangled in the inner regions of the root ball (difficult to detect unless you loosen the roots apart and remove what soil you can), and this can slowly deprive a plant of the resources it needs for growth because the roots don't establish.
Miri
Pines are sensitive to poor soil drainage as well as drought, so perhaps the roots stayed too wet or dry at some point prior to the browning. Frustratingly, evergreens sometimes take weeks or longer to manifest symptoms of a problem, so tracking it back to a single event can be difficult. Although a handful of insect pests and fungal diseases can attack pine, they typically do so once the plant is already under stress, even if that stress isn't yet obvious. Plus, their impacts on the tree tend not to be terribly sudden in terms of needle death, with the exception of root rot due to soil conditions.
If multiple plants in that area of the yard have succumbed, that suggests something in the site conditions isn't suitable for them, such as the aforementioned soil moisture level or perhaps heavy soil compaction. You can try replanting new trees in spring if you prefer, in case this was a fluke, or switch to a different evergreen depending on what you might suspect the issue was. For example, if you know the soil stayed wet for awhile after rain, American Holly can be a good candidate. If too dry or you aren't able to irrigate during drought, then Juniper might work better. The majority of evergreens need full sun to thrive (6 to 8 or more hours of direct light in summer) though hollies are excellent for tolerance of moderate shade. A lack of enough summer sun wouldn't be responsible for this particular dieback in the short term, but over time it's a factor to keep in mind if considering a replacement.
Lastly, if these were relatively new plants which came from the same source, maybe their root systems were in poor condition upon planting and it took this long for them to decline to the point of dieback. Sometimes nursery-grown trees become quite rootbound before they are sold, or their roots get tangled in the inner regions of the root ball (difficult to detect unless you loosen the roots apart and remove what soil you can), and this can slowly deprive a plant of the resources it needs for growth because the roots don't establish.
Miri
