Al, I appreciate the explanation. I assumed there was a reason you specified pine, but wasn't sure. Mulch it is. We're going out to look at potting mixes today. There are 2 good local nurseries, so I hope to find some nice premade ones. Depending on what I find, I may get some pine bark fines or perlite to stretch them. At least one of them carries the pine bark fines. We're only filling 2 containers right now, so taking the easy way out. Otoh, I suspect that once we see what 6CF of good mix costs, we may well make our own in the future! Btw, I've recently read several mentions of lignins in human nutrition. Apparently their consumption is problematic for a lot of people, but not all. If anyone is curious about lignin in wood, here is a nice little Wikipedia article. Here is a link that might be useful: Lignin

I use (or some minor variation of) a mix made from: 1 part pine or fir bark (small uncomposted chunks) 1 part Turface (calcined clay granules) 1 part crushed granite gypsum (for Ca) micronutrient granules (Micromax) for all my (250 or so) containerized trees It's extremely durable (structurally), holds air VERY well, will last long beyond the time you should have repotted. Al

Actually the Farfard #52 is considered a reasonable replacement for the gritty mix, not an additive. I would feel comfortable using it in its entirety for a potted JM - I use a prepackaged soil mix very similar to that myself for all my JM's.The other Farfard mixes that are usually available in retail outlets don't quite measure up in terms of quality and durability. Can you ask your source to special order the #52 for you? If unable to take this shortcut with the Farfards #52 and continue on with your homemade gritty mix, I'd persist in my quest for bark fines. Using another soil mix is just not an appropriate substitute. Bark fines can often be found under the label of "soil conditioners" - and they do not have to be pine. You can also often find them sold in pet stores as reptile bedding ( at a pretty inflated price, btw).

Your indoor Japanese maple doesn't look good because Japanese maples are not intended to be grown indoors!! They are not sold as houseplants and anyone who told you it could be done is misleading you. Plants that grow naturally outdoors in temperate climates - like Japanese maples - do not thrive in indoor conditions. There is insufficient light availability and the heat and lack of any humidity is often not to their liking. Plus, all these kind of temperate climate plants need a period of dormancy - winter cold temperatures - that are just not available indoors. This dormant period resets their biological clocks each season and not allowing them to go through this natural and very necessary process by keeping them indoors will weaken the plant to the point where it will eventually die. You can repot all you like and improve drainage but it is not going to improve the long term health of the plant. The only solution for this is to plant it outside where it belongs.