Question
QUESTION: We have two red maples planted three years ago and their leaves are limp. My neighbor's maple trees are fine. They look like they are dehydrated but do not respond to watering.

ANSWER: Check the trunk for wounds or injuries such as cracks and splits in the bark.  These would be signs of cold injury and, although not good, can be worked with.  Overwatering the trees could also cause a root rot which would cause the limp leaves.  Also--check for bugs on the limbs, such as scale, which would look like little brown oval bumps closely appressed to the bark.  Check each of these possibilities and respond back with your observations.  I await your response.  Thanks.

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QUESTION: No wound on the bark. There are small soft, smaller than a dime,same color as the trunk, spots on the trunk of the tree that can be scraped off easily with a fingernail. I checked other new maple trees in the neighborhood and they do not have this. Also some of the leaves are turning yellow. Thanks. ann

Answer
The tree may be infested with scale insects.  Your description sounds a little large, but there are some big ones out there.  I would treat the tree with Bayer Advanced Tree and Shrub Insecticide.  The product is mixed with water and poured on the soil around the base of the tree.  It is taken up systemically and will kill the bugs within a week or so.  It provides up to a year's worth of protection from reinfestation.  I hope this helps.  Thanks.