Hi Diana,

Thanks for sending in the pictures, and sorry about your pear tree! In order to better help you understand what's going on with your pear tree, we have some follow-up questions:

- Can you please send pictures of the entire tree and surrounding area, as well as close ups of the trunk and undersides of the leaves?
- What kind of pear tree is it?
- Where is the tree planted in your yard?
- When did you first notice problems with the tree, and has this happened before? Is the whole tree affected?
- Was this tree hit by hail?

On the leaves:

- Have you noticed honeydew, sticky leaves, or insects/any signs of insects on the leaves?

On the trunk and branches:

- Is there any damage or insects?

Basic care questions:

- What is the watering schedule for the tree, including in the winter?
- Do you fertilize the tree or the surrounding area?
- Do you use any pesticides in your yard/on your tree?

Thank you, and we look forward to hearing back from you!
Caitlin W. and Jessie A.

Hi Diana,

I'm sorry to see the decline in your pear trees. 

Based on your photos, I am wondering about the base of the smaller tree at the end. It appears that the pear that is struggling next to it may be planted too deep, and I suspect that is the problem with the smaller one also. Trees should have a widening at the base where they meet the soil, called a trunk flare. Your one tree looks like a straight telephone pole going into the ground. 

When trees are buried too deep, they suffer a variety of issues, including oxygen deprivation to the roots, causing them to send new fine roots up to find oxygen that eventually grow bigger and become trunk girdling roots. It can also make a tree more susceptible to disease and pests because the tree becomes weakened.

Were the trees planted when the hardscaping was installed, or was the patio and raised planter installed around the trees? While not very deep, your raised planter might not be the best place for a tree. On one side, it has no where to grow roots except down and under the brick pavers, an area that is undoubtedly compacted. 

It would be recommended to try to remove some of the soil around the base of your trees to try to find the trunk flare if possible, removing any landscape fabric also. It would be advised to monitor the moisture in the area. Your leaf spots do not look like a fungus in your photos, it is likely a sign of root problems with your trees. The chlorotic yellowing is likely due to a lack of oxygen and water stress (too much or too little) with the roots.

Here is more information about trees planted too deep:

https://extension.psu.edu/are-my-trees-buried-too-deep

https://dam.assets.ohio.gov/image/upload/ohiodnr.gov/documents/forestry/uftoolbox/PerilsPlantingTreesDeeply.pdf

https://extension.umd.edu/resource/trees-planted-too-deeply/

Here is the International Society of Arboriculture's website, to find a certified arborist:

https://treesaregood.org/findanarborist 

If your leaves develop spots again this year and you are concerned about a fungus, you can submit a sample to the CSU Plant Diagnostic Clinic. They can determine what fungus, if any, your trees may have so that you can use a correct fungicide and know when to time it. There are limited windows when fungicides actually work. Most fungicides are used when it has no effect on the organism, and you always need to be cautious of phytotoxicity. 

https://agsci.colostate.edu/agbio/plantclinic/

I hope this helps!

Dawn



Hi Diana,

Thanks for more photos of your trees!

It looks like your tree(s) might have multiple issues going on. 

First, it looks like your tree may have a past frost/freeze crack in the trunk. It looks like the older bark is peeling off and its just bare wood underneath, with a small vertical crack in it.

I can't be certain based on the photo. Take a look to see if there is new bark under that old peeling bark, or if there's no bark and a crack in the trunk. If there is a crack, then this is past freeze damage and sunscald. Wrapping young trees in winter can help prevent this damage. Here's more information on this:

 https://extension.colostate.edu/resource/environmental-disorders-of-woody-plants/

I also think you have a lot of root problems going on in your trees. In the photo before you cut the grasses and pulled the mulch back from the trunk, when zooming in, it looks like there might be a trunk flare. It could be the shadows but it also looks like you could have trunk girdling roots too. It is difficult to tell when zooming in.

Take a look at this area and see what you can find. Here is more information about girdling roots: https://extension.umd.edu/resource/girdling-roots/

Here is another great publication about what happens to trees with girdling roots. 

https://henderson.ces.ncsu.edu/news/girdling-roots-hidden-and-silent-killer-of-trees/

Please read this one above, you might find that some of the descriptions about branches dying off with girdling roots corresponds with the photos of your healthier tree next to the one on the end (sent summer 2025), with some entire branches yellowing, while other entire branches are all green. These symptoms are indicative of root problems. 

I can understand why you tried an iron spray on your trees, the past photos you sent show severe iron chlorosis with interveinal necrosis (photos didn't show signs of a fungus). 

There are many causes that contribute to iron chlorosis in plants but a lack of iron in our Colorado soils is not usually one of them. Calcareous soils, over watering, soil compaction and trunk girdling roots also cause it, along with plant competition, winter injury and soil organic matter. Here is more information about iron chlorosis in woody plants and how to correct it: https://extension.colostate.edu/resource/iron-chlorosis-of-woody-plants/

From what I can see in your photos you have soil compaction in the root zone under the patio, possible trunk girdling roots, possible plant competition, and possible winter injury with the sunscald and trunk crack. 

It would be recommended to pull back your mulch and find the actual soil level, and then dig down to find your roots. The number one cause for tree decline and death we see in landscapes is planting too deeply. Sometimes, trees can even come from less than reputable nurseries and bog box stores with soil packed over the original root ball and are already too deep in the nursery containers. When planting, it is always important to inspect the root ball, whether in a black nursery pot or balled and burlaped, to find the root flare and make sure it is planted above the soil line. Here is more information about tree planting steps and the science of planting trees: 

https://extension.colostate.edu/resource/tree-planting-steps/ 

https://extension.colostate.edu/resource/the-science-of-planting-trees/

Also, if you have any landscape fabric or weed barrier under your mulch, it would be recommended to remove it. Weed Barriers prevent proper water and oxygen exchange with soil and can further contribute to girdling roots. 

It is never recommended to mulch over the root ball of a newly planted tree, and mulch should always be kept away from the trunk. Mulch near the trunk harbors moisture, pests and invites disease at the base of the tree. More about mulching: here: https://extension.colostate.edu/resource/mulching-trees-and-shrubs/

I wish I had better news for you, but the symptoms you are seeing in the canopy do appear to be due to root problems. Removing the mulch from the trunks and any weed barrier will help, and doing a good inspection/investigation of the roots might give more answers. While it doesn't appear you have a fungus, the cause of your iron chlorosis is likely due to root and soil problems.  

A soil test wouldn't be a bad idea, just to rule out calcareous soil and to know what is going on in your soil. You can get a soil test here: https://agsci.colostate.edu/soiltestinglab/

Here is how to take a proper soil sample: https://agsci.colostate.edu/soiltestinglab/soil-water-plant-testing-laboratory/soil-sampling/

I hope this helps,

Dawn

Hi again Diana,

One more thought I forgot about your trees is watering. 

Too much or too little water can stress a tree, making it more susceptible to pests and disease. I know you mentioned your trees are watered by drip irrigation when needed.  

Does 'when needed' mean the trees aren't normally watered on a consistent basis, only when we don't get precipitation? With the severe droughts we have been in the past several years, it will be important to monitor your soil moisture and water the tree when we don't get precip and the soil is dry. If you haven't winter watered your trees this season they are likely drought stressed from our unusually warm and dry winter, and you might think about adding some supplemental water this spring. 

Here's info about fall and winter watering of trees:

https://extension.colostate.edu/resource/fall-and-winter-watering-of-plants-and-trees/

While soil conditions and tree species will vary, on average most mature trees need 10 gallons of water per inch of trunk diameter at each watering, and water should be reapplied when the top 4-6" of soil dry out. It's hard to gauge the DBH on your trees from a photo, but I would say around 5-6", so your trees would need at least 50-60 gallons of water each time you water it. 

Never water at the base of mature trees, it does nothing good for the tree.  You want to water at the dripline of mature trees, which is where they canopy extends out to. That area is where the fine feeder roots that absorb water grow. The tree base only has woody roots that can be susceptible to rot when sitting in soggy soil. 

One of your photos showed some spaghetti tubing where you moved the mulch back. It would be recommended to check where all your drip emitters are so that when on, they are watering at the drip line of the tree and not near the trunk. It would be recommended to check the gpm on your drip emitters also, to make sure you know how much water they are delivering to ensure it is enough for what the tree needs. 

Investing in a moisture meter to monitor whether the soil is wet or dry would also be a good idea.

Thanks,

Dawn