Gardening and Horticulture - Brown Spots on Maple Leaves

We just got an autumn blaze maple a few months back and now that it is in full bloom, I have noticed that some leaves (maybe 1 in 100) have a couple pea sized brown spots on them. The tree is probably about 5 years old. Is this anything harmful?

I have read that tar spot is not anything to worry about if this is indeed what it is, is that true?

Also, is it natural for a young tree like this to shed a few more leaves than a full grown tree? I ask because I noticed a few more maple leaves on the ground than usual...but this may be because it is windy. Thoughts?

Hope you planted this fast growing beauty in an area away from the house and where it has plenty of room. It can grow three feet a year and will reach 50 feet tall and 40 feet wide. It's too large for an average yard, that's why you usually see it in parks.

There are several fungal diseases that can cause spots on maple tree leaves. Usually if tree is not stressed from under or over watering, is planted in soil with good drainage, and receives proper fertilizer until established, it tends not to succumb to disease. You can take a couple of the affected leaves to the local Cooperative Extension Agent to be sent off to the state lab for free diagnosis. If fungicide is required, these are best applied in spring before buds break.

For photos and more info on leaf spot on maples, go to http://www.extension.umn.edu/yardandgarden/ygbriefs/p414anthracnosemaple.html