Here in Georgia, we have pine straw (needles) which are a nice brown color & break down rather slowly. They make a wonderful mulch, but I don't know if you could get them cheaply on the west coast. Samantha
I don't think you'll find much difference in the amount of moisture held by different mulches, just in the appearance, or how long it lasts, or stays in one place, or cost.
Samantha, I'd love to use more pinestraw but we don't even get that around here very much.
hmmm. always heard not to use mulches that retain serious amount of water on my irises. but pine straw is fairly safe in light amounts. just increases soil acidity, so have to keep that in mind. acid loving plants, camellias and such, love pine straw.
if you are looking for best water retention, then pine straw not good unless very very deep.
Dun1kirk, do you have coastal live-oak leaves in Berkeley? We had lots of them in Monterey, CA, and the leaves were readily available, organic, and relatively small so the mulch didn't mat up. They are acid, so acid-loving plants are particularly happy. Just keep the mulch slightly away from the crowns of your perennials.