Knowledgebase
Diagnose problem with Dwarf Blue Swiss Stone Pine Trees #865531
Asked April 23, 2024, 7:30 AM EDT
Dakota County Minnesota
Expert Response
Dear Judith,
Thank you for reaching out! I have a few questions that may help with determining the problem:
1. When did you notice some of the needles start to turn brown? Is it a certain time of year, i.e., spring?
2. Do the brown needles fall off easily? Do they fall off during the summer or fall?
3. Do you notice any small black, tan, or brown spots on the needles?
Thank you for answering these!
- the discolored needles appear year-round
- the needles do not fall off easily, but there is definitely more needles underneath the sickly tree than the healthy-looking tree.
- there are no spots on the needles. the discoloration appears mostly on the tips
Dear Judith,
Thank you for the additional photos, that is very helpful! Since the tips of the needles are brown, the problem could be related to winter injury or de-icing salt. Here is a helpful UMN Extension article on protecting your trees in the winter: https://extension.umn.edu/planting-and-growing-guides/protecting-trees-and-shrubs-winter
However, given only one tree is affected, it may be best to contact a certified arborist or send in a sample of the plant to the Plant Disease Clinic to make sure that the tree isn't diseased. Here are links with more information:
UMN Plant Disease Clinic: https://pdc.umn.edu/
Hiring a certified arborist: https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional
Good luck!
