I haven’t tested the pH, but I can say that the 100% pine cat litter pellets at least do not kill blueberries, lol.
The pellets easily fall apart to make sawdust. I have 2 new little blueberries that I potted up using a great deal of this, and they look awesome. It’s only been a few weeks, but I thought I’d pass on the idea as an experiment in any case.
I got a big bag for $9 or so, and they expand when wet. Then they crumble into sawdust.
I used these and sphagnum peat moss, a bit of native red clay, and some dry, old leaves for my potting mix. I mulched with the pine cat litter, too. I have no pics, but they are just green, with nice new green growth They were teeny, boxed bareroot plants from Lowes.
I’ll have to fertilize, but I am like others wondering what acidic materials can be used to make the ‘soil’ for blueberries. My clay is good for acid, but its texture is bad (alone) for shallow roots. Peat and my clay get too hard and dryish on top, too. The pine addition makes things much more crumbly and nice.
It’s more like weathered a bit. Just left out in the sun and rain for a week or so, with nothing else added. The pine litter I got was pressed into pellets. Feline Pine, I believe and can check tomorrow.
I do fertilize them here and there anyway. Our soil texture is just so hard for blueberries. Peat is great, but it dries in the top layer in summer and is hard to get wet again.