Acidic hugelkultur

I'm thinking using some very punky larch trunks and some bales of peat moss I bought before I became enlightened to build a hugel. If I want to make a bed where I can plant blueberries and some other ericaceous, useful plants (and one rhododendron, which I can't bare to kill), do I have to mix the peat with soil, or can I saturate the bales and use them with a good cover of leaves? Should I use other wood, in addition to the larch? I might be able to get some alder and poplar stumps, and I have a pretty good brush pile with prunings from bushes and trees. What do you all think?

I think you do need soil. I've made lots of lasagna needs and hugelbeets over the years and the best ones are a mix. If you don't add soil it's just compost, you need sand, silt and clay to make soil which holds on to nutrients.

Thank you. I've seen beds made for rhododendron that were pure peat, but you're probably right.

Save the peat for seedlings that need a sterile medium. Mix with coffee grounds and some lime.

@Dale Well, yes, but what I've got here is 8 x 30 kg. bags of compressed peat (spaghnum moss). That's a lot of seedling medium! Probably a lot of lime as well, as the PH of this stuff is between 3,5-4,5. ;P

I agree with Matu about the soil, silt and clay. Perhaps you can access some seaweed. If seaweed and lots of shells were mixed with the peat, it would absorb many nutrients. I still say use coffee. It's free here and available in dozens of places. Leaves should only be limited by supply and time constraints. If I could have a pile 100m tall delivered for free, I'd say yes.

If you are preparing the soil for rhododendrons don't add lime to it. They hate it. You can grow them in high pH soil, as long as the pH is coming from a lot of magnesium and not calcium.