Choose Flying Engine - Open Engine settings, and on the "Collect" tab, add "Dark Soil" to the Herb List. If you do not have Herbs on this toon, you might want to remove the others from the list, so it doesn't try to collect those too.
Make sure you have herbs selected in the engine settings, and you are all set.
PS: You can backup your "Collect List" its in the collect folder where LB is installed.