Question
I have two questions.
First, we have a large maple tree in our back yard and the trunk and one limb
are showing new large nodules all over -- like bumps in the trunk.  

Second, we have two oak leaf hydrangeas and the leaves look very spotty --
almost like rust.  

Any cures?

Answer
Let me address the hydrangeas first.  If the spots are brown in the middle with a purple border, the plants may have a fungal leaf spot.  If this is the case, I would treat the plant with Daconil fungicide which can be bought at good garden centers.  I would remove as many of the affected leaves as you think the plant can stand and destroy them before fungicide treatment.  I would re-treat in 7-10 days and then I would sit back and see if more show up.  If they do, you may have to treat a third time.  Try not to water overhead as this spreads the fungal spores on the plants.

As far as the maples are concerned, can you respond with a little more information.  How large are the bumps?  How many? Location on the trunk (how far from the ground)? and any other information such as weed eater wounds or any other physical injury the tree may have suffered.  I await your reponse on the maples.  Thanks.