Yellowing Ponderosa Pine Tree (not a fall occurrence)

Asked August 21, 2019, 6:01 PM EDT

I have a 30 -year old Ponderosa Pine that started yellowing last year. It just coned out earlier this year and is still growing, but as you can see from the aerial photo, it is the only Pine tree on my property turning this color (look at the southwest corner of my house in the center of the photo). North of the house is a maple. Could it be a beetle or a fungus? If so, how do I tell? It is our favorite tree.

Water is not the issue. I haven't turned on my lawn sprinklers all summer as we have had rain several times a week on the Palmer Divide north of Colorado Springs.

I also attached a pine needle photo. The needles are dying out here and there and I see green growth in between dark brown on the needles before they die out.

Any help diagnosing and treating this treee is very much appreciated!

El Paso County Colorado

11 Responses

Thank you for your question about your yellowing Ponderosa pine Tree. I think I can see a yellowing patch in the overview of your property. It looks like you could have ‘Ponderosa Pine Needleminer’. Please take a look at the fact sheet below to see if the description matches what is going on in your tree.

I have also attached a page from our book, 'Insects and Diseases of Woody Plants in Colorado', which has some nice pictures of the damage caused by the Ponderosa Pine Needleminer.

Thx Barbara. I don’t see a hollowing of the needles so I am not sure this is it but I will give the treatment a try. What I do see is sections within the needle dying off and the base is green. I attached a few more pics.

Good Morning,

Thank you for your reply and additional comments and pictures. I am going to reassign your question to Frank Peairs, Professor of Entomology, Larimer County, who is associated with our Ask an Expert Program. You should be hearing from him in a couple of days.

Good Morning,
I wanted you to know I have not forgotten your question about your Ponderosa Pine.
Your question was assigned to a couple of our CSU professors but we have not received an answer. In case you still have concerns about your pine, I have included a link below which will take you to a list of licensed tree services in Colorado Springs. An arborist may able to help you with your question.
I have also attached another tree services list from our El Paso County Extension office.

Hi, I have learned that your question has been assigned to Tamla Blunt who is active in our Ask an Expert program. I hope that you will an answer soon.
Thank you for your patience.

Thank you for the support. I am going to have to get someone out here to take a look at it soon. It is so strange that this is the only tree I can find in the neighborhood with this problem,

Is your house the one in the middle (in the aerial photo)? Is there a way to circle or point an arrow toward the tree (in the picture) that you are talking about?
The needle damage (from the needle photos) does not look like an insect or a fungus, from what I can see. Is this tree located among a lot of other ponderosa's? Did you measure the amount of water (from the rain)? Has their been any construction or digging around the tree in question?

Thank you for your answers.

I have circled the tree in question. The other tree north of the house is a red maple and has a similar color in the aerial photo.

I live on the Palmer Divide in Black Forest. I did not turn on my lawn sprinklers until early August as it rained almost every other day until then. Electronic rain gage says 53 inches of water this year but I don’t know how accurate it is.

All other pines (about a hundred on property) and aspens are doing well. No construction or change around the tree. If no fungus or disease, then I am wondering if it’s proximity to the house or if the area under the canopy needs its own water supply as it has grown. But I don’t see this problem with other neighborhood trees next to houses.

Thank you for your answers. Have you had the soil tested for pH? Was this tree there when the house was built or was it planted after the house was built?
Thank you.

The tree was moved from the back of the lot 23 years ago. ph has been tested. I will find the report. Added another picture to show the striking change from the other trees on the lot.

Thank you for your responses. Yellowing can be caused by a lot of different things. Iron chlorosis can happen, even in pines. It could be drought, too much water, girdling roots, spider mites can cause needles to yellow. Tip dieback could be due to sudden cold temperatures, stress on the tree.

Have you checked the soil around the tree to see how moist it is? I generally recommend a long-shanked screwdriver (10-12 inches) to test the soil. If the screwdriver penetrates the soil easily, then the soil is probably moist enough. If the screwdriver is difficult to get into the soil, then the soil is too dry. And if it pulls up mud, then definitely too wet. Does the landscape drain towards that tree or away from the tree? It looks like the tree should have plenty of space for the roots to grow, it doesn't look like it is too close to the house but I can't tell what the drainage situation is. However, the grass in that area doesn't look as green as the grass towards the front of the house so it makes me wonder if the back area is not getting enough water.

Thank you,