I have herbs scattered throughout my veggie garden. I planted borage three years ago and haven't needed to plant it since, as it self sows joyfully. Speaking of joy, that it how the bees must feel about it. It is covered in them!
When it gets too big, I cut it off at the base and lay it on top ov the soil or add it to the compost. I also heard squash bug won't cross it.
Bergamot is also scattered among my veges. I don't have a problem with lack of fruit set. I grow chives just to cut and scatter around the base of all my plants. Although not an herb, nasturtiums seem to confuse bugs.
I have all the basic herbs scattered about. It is jumbled, messy, rambunctious, but very productive. No two plants are the same next to each other. I don't want to set up a convenient buffet for the pests. If they have to work too hard to find food, they will go find a conventionally planted garden.
Variety is the spice of life!
