Correctly selecting the foraging method will provide you with up to 7 deben of that herb and indicate the name of successfully foraged herb. The amount harvested appears to be correlated with the amount of time that herb has been there. Confirmed by harvesting an herb that spawned and getting only 1 deben.
Initial Google sheet: T11 Herb Worksheet
These tools at the moment are a common way of tracking and maintaining the herb information within the community.
Note: This Tale, I'm going to have my pages auto-import from the wiki instead of manually copy/pasting results from T10 Google Spreadsheet.
Feel free to continue using the Spreadsheet (if that is your preference) but be sure to update the wiki with the confirmed Methods and Stats. ~Cegaiel