Also, hard row to hoe. A difficult course, hard work to accomplish, as in He knew he'd have a tough row to hoe by running against this popular incumbent. [First half of 1800s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.