Hello Laurel,

Thanks for reaching out to Ask Extension about your Big Tooh Maple tree! Thank you also for the great pictures.

The damage you are seeing on your tree looks like it is from past hail damage, not necessarily from a disease. It's one of the reasons you see the damage on the top of the limbs. It also looks like it is older damage, as it has calloused over a bit since the damage occured. 

Unfortunately, this kind of damage can open the tree up for pests and disease. From your pictures alone, I cannot tell that there is any signs of disease. I'm sure the tree has been stressed since this damage occured which can also make it more susceptible to pests and disease. 

The best thing you can do for your tree at this point is to give it some good TLC and proper care. There is nothing that you can do about the past damage, but moving forward concentrate on giving it proper water (remember over watering is NOT good), and making proper pruning cuts when necessary and continue monitoring it for changes. 

Here is some information about fall and winter watering, which is the time you should really monitor the amount of precipitation we get (or more often don't get).

https://extension.colostate.edu/topic-areas/yard-garden/fall-and-winter-watering-7-211/?_gl=1

Also, here is more information about proper pruning. 

https://planttalk.colostate.edu/topics/trees-shrubs-vines/1724-pruning-shade-trees/

https://cmg.extension.colostate.edu/Gardennotes/612.pdf

If you have any other questions, feel free to reach out to me directly.

Thanks Laurel,

Dawn Fradkin

Horticulture Programs Coordinator, CSU Extension Arapahoe County 

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Hey Laurel,

You are correct! I do remember your tree, I planted it... :) Thank you for your kind words.

If you have more questions, feel free to reach out to me directly.

Thanks,

Dawn

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