I like to use pine straw, Loblolly or Longleaf, as it's been shown that it inhibits the germination of certain seeds. It truly seems to help with weeds in the veggie and herb gardens.

If pine straw is not available to you, almost anything can be used....wood chips (which is what I use in my ornamental beds), conifer bark, etc.

What look are you wanting? I prefer a shredded fine mulch. I would definitely avoid anything dyed, so stick natural.

We don't know where you are growing these herbs, but since the rosemary, thyme and basil hail thrive in Mediterranean climates I'd question their need for mulch at all. Especially the ground hugging thyme. In my climate mulch would just cause them to rot.

I use a heavy mulch of oak and maple leaves in the fall to winter in my herb bed. Then in the summer I use heaps of grass clippings for mulch.

My tarragon is a bed eating monster that I have to keep cut back, my thyme plants are gaining ground. My rosemary and basil I grow in pots because rosemary can't quite hack the winter exposure, and basil dies right off. My mints, chocolate and pineapple, are in their own area, and don't require any mulch at all- they are extremely vigorous on their own.

That's why we need to know where the OP is gardening. Winter wet makes mulch a suffocating, soggy, slug infested killer for Mediterranean type plants in my kind of climate but clearly preserves life in beesneeds colder Winters.

I don't mulch the herb garden -- especially the Mediterranean herbs. It is too moist here as well and the mulching would cause too many problems.

FataMorgana