Maintenance of a Eucalyptus tree - Ask Extension
I have a eucalyptus tree, about 20 feet tall, that's been in the ground about 15 years: healthy until the last 2 years. About 50% of the crown has no...
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Maintenance of a Eucalyptus tree #894997
Asked March 20, 2025, 4:51 PM EDT
I have a eucalyptus tree, about 20 feet tall, that's been in the ground about 15 years: healthy until the last 2 years. About 50% of the crown has not produced leaves the past few years: instead I get a lot of lateral growth off of the branches. It's been through a few ice storms and is cold hardy to the teens, so I don't think it's the weather. Would you recommend fertilizer (even though it naturally grows in gravelly soil)? Could it be at the end of its normal life span? Maybe a shot of fertilizer will send new growth up to the crown.
Not sure what, if anything, I can do about it.
Thanks
Multnomah County Oregon
Expert Response
Hello William and thanks for your questions concerning your eucalyptus tree. Although a picture would help, I'll make a few suggestions.
The lifespan shouldn't be a problem as they can often live for hundreds of years. There is a longhorn boring beetle that may attack and kill branches, but you would see sap oozing out of those upper branches if this insect was present.
Sometimes a stressed tree (heat, cold, water, drought) will shed branches and the fact that you are getting lateral branches means the tree is still trying to stay alive. Prune off the dead branches and know that our climate changes are stressing nearly all our trees.
And finally, sometimes eucalyptus trees will just naturally shed older branches, especially in cooler climates. I would expect to see that from this winter's temperatures, but not sure about last year.
As eucalyptus can be over fertilized, especially mature trees, it would be wise to get a soil test before you add anything. You can have this done at the following site which will tell you what to send in to them:
https://al-labs-west.com/soil-analysis/
Hope this helps,
The lifespan shouldn't be a problem as they can often live for hundreds of years. There is a longhorn boring beetle that may attack and kill branches, but you would see sap oozing out of those upper branches if this insect was present.
Sometimes a stressed tree (heat, cold, water, drought) will shed branches and the fact that you are getting lateral branches means the tree is still trying to stay alive. Prune off the dead branches and know that our climate changes are stressing nearly all our trees.
And finally, sometimes eucalyptus trees will just naturally shed older branches, especially in cooler climates. I would expect to see that from this winter's temperatures, but not sure about last year.
As eucalyptus can be over fertilized, especially mature trees, it would be wise to get a soil test before you add anything. You can have this done at the following site which will tell you what to send in to them:
https://al-labs-west.com/soil-analysis/
Hope this helps,
