Austrian Pine Turning Brown on Top and Body - Ask Extension
We planted Austrian pines 1.5 years ago in summer. Made it through first winter. Winter was dry less snow cover and windy. Watered as needed. New grow...
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Austrian Pine Turning Brown on Top and Body #548308
Asked March 22, 2019, 10:41 AM EDT
We planted Austrian pines 1.5 years ago in summer. Made it through first winter. Winter was dry less snow cover and windy. Watered as needed. New growth and healthy second summer. Watered and fertilized as required and needed. Used moisture gauge to determine watering needs. Second winter, more snow cover, less wind, but colder consistently in teens and 20’s over night. Austrian pines turning brown on top and body. These look likely they are going to die. The blue spruces we planted are much more resilient. We are at 9900 ft in South Park. Other Austrian pines we planted last summer were chewed on by deer. They look bad, as well. They don’t look promising as to whether the missing needles will recover this spring and summer.
What is the reason for the die-off going into the second year? I have read if they can make it through the second year chances are higher for survival. No more Austrian pines. We are going to stick to Blue spruces.
Thank you for advice and guidance.
Park County Colorado
Expert Response
Hello,
Thank you for your photos and description. I suspect that the damage this second year is due primarily to the colder temperatures. Since you winter watered the first year, and mother nature watered more this second year, moisture is less likely an issue. The main factor in your situation is your 9000 ft. altitude. The native range of the Austrian Pine (Pinus nigra) is in mountains of the northeastern Mediterranean region, at elevations of 650 - 6500 ft. On average, temperatures decrease 5 degrees (F) for every 1,000 foot increase in elevation: the Austrian pine is not suited to the reduced temperatures and humidity at 9000 ft. This is consistent with the needle scorch shown in the photos you sent. Altitude has an impact on plants that isn't captured in the USDA zones. Depending on the resource, P. nigra is listed as cold tolerant to zone 4 or 5. In the south Park area, you are likely zone 4, based on temperature, but probably lower based on microclimate.
Management Recommendations:
If you decide to replace the trees, choose native evergreens. There are no non-native evergreens recommended for above about 6500 ft. In addition to the Blue spruce you mention, you may consider varieties such as Englemann spruce, Limber pine, Ponderosa pine, Douglas Fir. See the CSU Fact Sheet on Native Trees: https://extension.colostate.edu/docs/pubs/garden/07421.pdf
References:
Best regards,
Thank you for your photos and description. I suspect that the damage this second year is due primarily to the colder temperatures. Since you winter watered the first year, and mother nature watered more this second year, moisture is less likely an issue. The main factor in your situation is your 9000 ft. altitude. The native range of the Austrian Pine (Pinus nigra) is in mountains of the northeastern Mediterranean region, at elevations of 650 - 6500 ft. On average, temperatures decrease 5 degrees (F) for every 1,000 foot increase in elevation: the Austrian pine is not suited to the reduced temperatures and humidity at 9000 ft. This is consistent with the needle scorch shown in the photos you sent. Altitude has an impact on plants that isn't captured in the USDA zones. Depending on the resource, P. nigra is listed as cold tolerant to zone 4 or 5. In the south Park area, you are likely zone 4, based on temperature, but probably lower based on microclimate.
Management Recommendations:
- The trees in first two photos may yet pull through this winter. Check to see whether new buds are viable (green inside). If so, watch and wait through the early summer to see whether they candle out this year. If they pull through this year and you decide to keep trying with them, use these winter protection strategies:
- Put down an organic mulch (e.g., shredded bark) beneath the trees: 4 inches deep, keeping mulch 2-4 inches away from the trunk to minimize insects and diseases), extending out to the drip line of the tree.
- In late fall before the ground freezes, give the trees a deep watering, getting moisture down a foot or more (depending on your bedrock depth).
- Hand water during the fall and winter whenever there has been no precip for 3-4 weeks and morning temps are above 40F.
References:
- Tree planting steps: https://static.colostate.edu/client-files/csfs/pdfs/TreePlanting_636.pdf
- Care of recently planted trees: http://www.cmg.colostate.edu/Gardennotes/635.pdf
- Gilpin County Extension Mountain Plant Recommendations: nhttps://gilpin.extension.colostate.edu/programs/mtn-hort/recommend/
- Conifer society - P. nigra: http://conifersociety.org/conifers/conifer/pinus/nigra/
- Selecting Trees for High Elevations:
- The Tree Farm Longmont Austrian pine: http://www.thetreefarm.com/pine-austrian
Best regards,
One other thought -
The Jefferson County 4-H sells seedling trees every spring. They are taking orders through Saturday April 6. Here is a link to the web site, where you can see tree species by elevation, along with contact information for questions or to inquire about availability: http://4htrees.org/
Best,
Mari
The Jefferson County 4-H sells seedling trees every spring. They are taking orders through Saturday April 6. Here is a link to the web site, where you can see tree species by elevation, along with contact information for questions or to inquire about availability: http://4htrees.org/
Best,
Mari
Thank you Mari for your reply to our questions. We appreciate your time you took to reply! We will stick to the native trees as you suggested.
You are very welcome. Thank you for using Extension's Ask an Expert!
