3.1 Herbs for groundcover.

Also see Growing chamomile, 2.7.1, above.

From: jera.ksu.ksu.edu
I've found the following plants useful as groundcovers. Unless otherwise noted, all are perennial, and hardy in my Zone 5 (north-central Kansas) garden.

• pennyroyal, Mentha pulegium
  Don't fertilize this regularly, it doesn't need the encouragement). NON-EDIBLE.
• lemon thyme, Thymus x citriodorus
  Otherwise known as the thyme that ate Cleveland; semi-evergreen in my garden.
• mother-of-thyme, Thymus serpyllum
  Semi-evergreen, turns a lovely bronzed-purple color in the winter.
• caraway thyme, Thymus herba-barona
  Used in the late Middle Ages to flavor baron of beef, hence the name. A very low, flat, spreading plant with a fascinating fragrance & flavor.
• oregano thyme, Thymus sp.
  Grows much like mother-of-thyme, wonderful oregano scent and flavor.
• Aztec sweet herb, Lippia dulcis
  Low, sprawling annual; odd, resiny scent; it's supposed to self-seed readily, cuttings root fairly easily.
• oregano, Origanum vulgare
  May be a bit tall for a groundcover, especially after 2-3 years; spreads vigorously; attractive flowers.
• germander, Teucrium chamaedrys
  NON-EDIBLE but fun, a broadleaf evergreen; great for rock gardens and retaining walls; attractive flowers.
• mints, Mentha sp.
  These may be a bit tall for many uses, but for a moist spot that's hard to mow, or that washes out frequently, give them a try - I've found that the candy-scented varieties are somewhat less invasive.
• chamomile, Anthemis nobilis + Matricaria recutita
  These don't grow well in my area, it's too hot and dry; one is annual, one perennial.

From mflesch.mail.coin.missouri.edu (Mary A. Flesch):
I can't believe no one has mentioned the mint family in this group. At my last house, I planted a tiny spearmint plant to have in iced tea (I'm originally from Louisville, KY and was also planning on juleps). By the time I moved 2 years later, I was able to dig it up and give to four friends while still leaving plenty for the new owners!