How to treat Pencil Pine balding on one side in Queensland?

[my2108]

I have a few pencil pine at my front yard and they have been healthy and require fairly low maintenance. 

But recently I found that the youngest two pine of the brunch are getting bald on the right side of lower trunk.    I attached two photos here, the first one was taken from the heavy one, and the second one was taken from the two balding ones.

Is there anything I can do about it.  Is that because of all the heavy rain here in queensland?  Cos the sick ones are both located at the downside of a small slope.

[MitchellMc]

Hi @my2108,

It’s possible that the issue is related to excess water, especially if these trees are positioned at the lower part of a slope where water might be pooling. However, if it were purely a water issue, I’d expect to see signs of stress across the whole tree rather than just one side. Does this area receive less sunlight during the day due to its positioning? Often, parts of a tree that don’t get enough light will thin out or die back since they’re not contributing to the tree’s growth.

It’s also worth taking a close look at the affected branches and foliage to check for any signs of disease or insect infestation. Look for discoloured needles, webbing, or any small pests that could be feeding on the tree. If you notice anything unusual, let me know and we can work out the best course of action. 

Please let me know if you have any questions.

Mitchell

[my2108]

HI Mitchelll,

Thanks for your reply.  You are right on, the balding side of the tree is facing the north (blocked by the retaining wall etc) so its receiving relatively less sunlight.

I checked the branches, there isn any major issued found except for 1-2 "bleeding" site, some needles do turn brown but its less than 5% of the total.

Hope thats the info you are looking for?

And I assume if its water stress, it will cure itself?

Thanks again for your advice.

[MitchellMc]

Any chance of some images of these "bleeding sites" @my2108?

Mitchell

[my2108]

HI Mitchell,

Photo 1 and 2 are from the baldest pine. (most further down from the slope)

Photo 3 is from the second baldest.

[MitchellMc]

You've got some issues going on there @my2108. 

The bleeding sap from the wounds suggests an infection, possibly from Cypress Canker or perhaps even mechanical damage. Cypress Canker is common in conifers and causes dark, sunken bark, leading to sap leakage as the tree attempts to defend itself. 

To address this, carefully prune back any dead or infected branches, improve drainage around the trees, and consider applying a copper-based fungicide to help prevent further infection. If the sap flow continues or worsens, it may be a good idea to consult an arborist for further assessment.

I'll call on our resident horticulturalist @Noelle to see if she has some thoughts.

Mitchell

[Noelle]

Unfortunately, @my2108 , I have to agree with Mitchell that your cypress appear to have a serious issue which looks like canker. While pruning back and using a copper fungicide may buy you some time, in my opinion the condition will ultimately prove to be terminal.

Once cypress become infected, progression is extremely hard to control and the wounds allow other problems to develop, such as rots and insect incursions. Sorry to be the bearer of bad news, but I think you should start planning to replace the trees sooner, rather than later.

[my2108]

HI Mitchell,

May I know how deep the pruning needs to get done?

I will pick up the cooper based fungicide asap...and I assume I just applied to the solil as indicated on the label?

I wonder if there is a separate instruction needed for Pine tree.

Martin

[MitchellMc]

Pruning only needs to be done to branches that have wounds on them and are infected @my2108. That side of the tree doesn't appear to have much branch growth. My comment was only intended if there were branches with a similar look to the trunk.

You can apply it to the soil and the plant.

Mitchell