I am using onions, shallots, garlic, and sweet potato vine to make borders in some places. I also use non edible support species like bulb flowers, Liriope grasses, and a few different species of spiderwort.
I have seen lavender used as a great border too. I bet chives would look neat as well, especially when flowering.
My name is Inigo Montoya, you killed my father, prepare to read a tiny ad:
Homesteading and Permaculture Bundle - More than 35 Things