Diseased pine tree, is it treatable? - Ask Extension
OSU Expert,
I read your article "Diagnosis table — Douglas-fir, oak and pine". Believe our backyard 12-ft tall 3 pine trees are experie...
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Diseased pine tree, is it treatable? #797170
Asked June 22, 2022, 12:27 AM EDT
OSU Expert,
I read your article "Diagnosis table — Douglas-fir, oak and pine". Believe our backyard 12-ft tall 3 pine trees are experiencing various degree of sickness. One tree crown was light green in the winter and now turned mostly brown. Next to it is a Cryptomeria, and next are two more pine trees. These two look still healthy gree, but i can tell one pine's needles are slightly lighter green. All three pine trees have some branches with brown needles (in the lower part of tree). An arborist (from Urban Forest Pro) came couple of days ago and told me all 3 pine and the cryptomeria has fungal and beetle attack. By injecting shots (to kill fungus and beetles, these trees will recover. Though he said the pine with brown crown has 50% chance, seeing the crown still has some light green needles). I want to get your opinion if injecting shots can save these pine trees at this stage. I googled, many article says if the pine has been attacked by beetles, you must cut it down as it is not treatable. I would prefer to save, but do not want to spend $400 per tree for shots ($200 for beetle, $200 for fungus, and a 3 year treatment) if they are barely alive. Appreciate your expert opinion asap, as we need to urgently decide what to do (treat or cut down)! If we cut, can we plant another tree next to it (we can not grind the root as the trees are behind retainer wall so equipment can not get there).
Thank you!
Xijue
Multnomah County Oregon
Expert Response
Hello,
I haven't received a response yet on email subject below, with reference #
#0067101
Diseased pine tree, is it treatable?
Appreciate if you can get back to me. We really need your expertise.
For pine with brown top.jpg I'd consider that tree a loss and would remove it. That damage could be caused by beetles, which go after stressed trees.
For 2 more pine.jpg, the damage is less severe and the trees are salvagable. The damage may or may not be caused by pests and diseases.
Drought stress from the last several hot/dry summers could also be the cause of the dead branches. Drought stress makes trees more susceptible to pests and diseases.
Have the trees been watered the last 4-5 summers?
If it is a disease, tip blight could be the culprit
https://pnwhandbooks.org/plantdisease/host-disease/pine-pinus-spp-tip-blight
Removing the damage branches is recommended int he link above. Also keeping landscape trees watered is key.
For pine lighter green.jpg the same reasoning applies as above.
If it were me, I'd prune out the damage branches now that it is summer and then water the plants deeply every month or so this summer and not get the treatments.
Keep the trees watered in the summer. Mulch the soil to help conserve water. Keeping plants from becoming stressed is the best way to prevent pests and diseases.
For 2 more pine.jpg, the damage is less severe and the trees are salvagable. The damage may or may not be caused by pests and diseases.
Drought stress from the last several hot/dry summers could also be the cause of the dead branches. Drought stress makes trees more susceptible to pests and diseases.
Have the trees been watered the last 4-5 summers?
If it is a disease, tip blight could be the culprit
https://pnwhandbooks.org/plantdisease/host-disease/pine-pinus-spp-tip-blight
Removing the damage branches is recommended int he link above. Also keeping landscape trees watered is key.
For pine lighter green.jpg the same reasoning applies as above.
If it were me, I'd prune out the damage branches now that it is summer and then water the plants deeply every month or so this summer and not get the treatments.
Keep the trees watered in the summer. Mulch the soil to help conserve water. Keeping plants from becoming stressed is the best way to prevent pests and diseases.
Hi Weston,
Thank you so much for your reply with a good deal of information.
I met 3 ladies who at OSU education booth at local Safeway parking lot 2 week ago. They told me you are the expert and the leader.
Since then, I have done more research and looked at the 2 trees several times to exam the issues I could find.
Luckily I found a tree tag, Pinus Flexilis (limber pine). While looking at info on limber pine, came across lethal white pine blister rust. The more I delved into it, the more it seems culpable. When we bought the home 18 month ago, I already saw many death branches, since then we already pruned out a few brown branches and this summer, more red flags. If it were beetle damage, the acceleration of progression would have been much faster to kill the tree. I could not found obvious entry/exit holes around the tree trunks. I wonder if white pine blister rust is more likely the cause. Since it could take years to do the damage (several stages in life cycle). We live in forest heights on the hills. There is a woody creek bed behind one street of home below us, and another woody creek 50 meters on the other side of our home. Lots of trees and under bushes there. I wonder if there are currant or gooseberry bushes or other likely hosts in the environment. I have attached several recent photos, some close-up for you. I see several red flags in both trees. There are many cankers on branches, dead or on some branches that still have healthy small branches with needles, but the main branches already developed cankers with will cut off water in time to cause death. I didn't found fresh needle point of blight tips. And more concerning some cankers are very close to trunk or immediately adjacent to trunk. I wonder if it is the blister rust, it would have made in roads to trunk already. Also I saw some orange stuff on trunk and branches, I can put words from reading, coming from sprouts of orange stuff. All of these, once you see the photo, may give a different prognosis - if pruning can save the trunk. Not counting on top, cutting out cankered branches(dead or live branches) would take out half of the lower to mid branches.
We have 3 sprinklers in the tree area. Last summer and this summer, we have watered them. It is possible we need to increase the time with more water. But so many cankers on trees seems more related to diseases than under water.
I'd like to give you a call, or if you could give me a call since there is only so much one can put info in the email. My main co concern is if the two trees are still savable, or pruning is only delaying the dying if the rust is invading branch by branch and into the trunk.
Many Thanks!
Xijue
408.667.6081
Hello again,
Great detective work.
I agree that it could be pine blister rust:
https://pnwhandbooks.org/plantdisease/host-disease/pine-white-white-pine-blister-rust
The first three photos in the second batch of pictures you sent shows a long, vertical seem in the tree.
This seam is worrisome and a sign the tee is in poor health and will continue to decline.
If it were me, I would not try to salvage these trees.
If you want to replant your pine, here's a great resource (for fee): https://osupress.oregonstate.edu/book/native-and-ornamental-conifers-in-pacific-northwest
and for free: https://landscapeplants.oregonstate.edu/search-conifer
Feel free to give me a call if you like<personal data hidden>
Great detective work.
I agree that it could be pine blister rust:
https://pnwhandbooks.org/plantdisease/host-disease/pine-white-white-pine-blister-rust
The first three photos in the second batch of pictures you sent shows a long, vertical seem in the tree.
This seam is worrisome and a sign the tee is in poor health and will continue to decline.
If it were me, I would not try to salvage these trees.
If you want to replant your pine, here's a great resource (for fee): https://osupress.oregonstate.edu/book/native-and-ornamental-conifers-in-pacific-northwest
and for free: https://landscapeplants.oregonstate.edu/search-conifer
Feel free to give me a call if you like<personal data hidden>
Hi Weston,
Now 3 trees are removed, I bought 3 different types of trees: Hollywood Juniper, Kay Parris Magnolia and variegated box-leaf azara. I was told the same pine in the same location may contract diseases in the soil. But with these 3 different trees, do I need to replace some soils, or can I just plant the trees (amend with existing soil)? Should I go further to do soil testing, and with which service?
Portland Stump Grinding will grind down the stumps, planting location will be about 1 foot away, but not too far away given we don't have much room to move (see photo).
PS: last weekend, our family visited the Portland Japanese Garden, wished we have done it sooner after we moved to Portland. What a beautiful setting with meticulous planting. What an eye opening experience and also the Lan Su Garden, two gems in a not too big metropolitan city.
Appreciate your further guidance!
Xijue Wang
408.667.6081
I would not plant a pine again in the same location.
There's no need to do any further soil testing.
Yes, wait until the stump is ground and the replant. If there is a lot of wood from the stump grinding in your planting hole, then you might add a little fertilizer to help get the tree growing.
Yes, the Japanese and Lan su gardens are amazing.
There's no need to do any further soil testing.
Yes, wait until the stump is ground and the replant. If there is a lot of wood from the stump grinding in your planting hole, then you might add a little fertilizer to help get the tree growing.
Yes, the Japanese and Lan su gardens are amazing.
Thanks! So even if the soil has fungus from removed pine trees, I don't need to spray any fungus-killing chemicals if I plant a different type of tree? It won't be on top of the grinded down hole, it will be a foot apart.
Xijue
Using a fungicide to treat the soil is not recommended. Planting new, different plants is recommended to break disease cycle.
Thanks! Yes, I am planting 3 different trees.
Xijue
