The correct format for titles in your sentence is:
Dear Editor of the Springfield Times-Courier, I am writing because your article “Local Elementary School Grows A Garden” made several errors.
So the option that best matches this standard (with italics used for the publication title and quotation marks for the article title) is:
Dear Editor of the Springfield Times Courier (italics), I am writing because your article “Local Elementary School Grows A Garden” made several errors.