I have just located purslane at the local supermarket in the garden section, and am thinking about buying a bunch to plant in between the other herbs. It's edible and helps hold in water, which is good for raised beds.. I'm also trying to find out if hollyhocks (a member of the mallow family) are edible, because then I'll plant them against the fence.
Just got rosemary and lemon thyme. The oregano and sage are taking over, and I'm just trying to fill a few gaps.