Welcome MKE Bob, hope you stop in at the the Boerner Botanic Garden on Sunday, Feb 24, between 10 am and 2 pm, its the kick off meeting for the Milwaukee Bonsai Society, and the format for this meeting is a bring your own tree for a group workshop, there will be a short (20 min) presentation/discussion, and the the rest of the time, mingle, and work on your own trees, or as I often do, wander about looking at everyone's trees. Normally the MBS meets the first Tuesday of the month at 6:30 pm at Boerner Botanic Garden, Hales Corner, southwest burb from downtown Milwaukee. It is a nice friendly club. (if you are not a member already). Say hello. I should be there. For the Tuesday, March 5 meeting Colin Lewis will be the guest artist, his bonsai books are generally excellent, especially after he moved to US and got a better understanding of our winters. The Milwaukee Bonsai Soc. also has a club library, where you can check out some of the books without having to buy them.
Leaf Mould in general is as RockM says, a composted organic product. Heath Mould is 'made up' term, most likely Leaf Mould collected from a Heath-Bog type environment. We don't have Scottish Moors habitat in this country. I think were one to really want to find this very specific type of leaf litter, only the cranberry growing regions of Wisconsin would be likely to have a somewhat similar environment. If you get up to Stone Lake or Crandal, you might be able to dig some up yourself, but shy of that, it is not available. There are better alternatives, check what the other guys in the MBS use, materials that are locally available and not overly expensive. We get that Cherrystone, crushed granite, which is a beautiful reddish purple, brown and gray color that makes a wonderful component in an inorganic mix with things like Turface MVP. One of our members bought a full semi load of 'Dry Stall' a nice light gray pumice for adding into mixes also, its in 40 lbs bags, and she brings some to just about every meeting.In only 3 years, just selling to our small (75 or so people) club, she has less than a third of a truck load left, its been popular with our group. Most of us use blends of inorganic media, with only minor additions of organics. But come to a meeting and see what we do.
http://www.milwaukeebonsai.org/bonsai_newsletters.htm
http://www.milwaukeebonsai.org/Newsletters/MBS201301news.pdf