Alright, this is a little unconventional but in the interest of making sure people have something to do while I'm gone, I'm going to post the general responses that the man's wife would give to the questions you're most likely to ask.
The adventurers reach the inn where the herbologist's wife and their child are staying, assuming they chose this path instead of going directly into the wilderness to look for him, and she is called from her room to meet them if they inquire about her. Upon being asked where her husband most likely is, she tells them that their child has an infection that can be cured by a very young deathroot leaf. If the plant sprouted more than a few days ago, the toxins would be too powerful and would harm their child as well as the infection. Because of its use in poisons, deathroot plants growing near cities are usually uprooted and burned, so he most likely would have had to travel into the wilderness.
