I took the picture halfway through potting, so it has a lot more soil now than before. I used 60/20/20 ratio pine bark / lava / pumice. Right now it's positioned under a tree with just a tiny bit of direct/filtered sunlight daily, and gets a heavy watering daily.
I keep seeing comments about keeping these moist/watered, but also I've read 4 stories now about rotting wisteria. What's a guy to think?
You DON'T want the soil to drain quickly. Wisteria is a water hog. You want water to sit in the soil for a while. The mix you have now is a bit too porous. You want finer soil particles. FWIW, wisteria is a forest dweller, preferring cool roots and full sun on its top. It uses other trees to climb up and overtop, while its roots remain in the cool forest topsoil--they generally are not deep rooted plants. Because they use OTHER trees to get height and don't use it for support, their wood is weak and not very durable. It's not really even wood, so much as it is a woody straw to drink water through.
That the wood is susceptible to rot, while the plant loves water is a problem you have to work with when it's a bonsai. Wisteria grow VERY strongly and typically, they can outgrow weakness and rot on their trunk simply by rerouting. In a bonsai pot, with constant pruning, that's more difficult to overcome.
Watering daily is fine, but you're going to have to check it twice or even three times a day when it's actively growing and the weather is warm--they can soak up an incredible amount of water particularly when it's windy.
Another word of warning DON'T put the container directly on the ground. The plant WILL find a way out wiht their roots and can pop up 25 yards away from the main trunk with very little visibility. Once they've escaped they can be a nuisance and even a danger (at least here in the Southern U.S. as they can tear siding off houses within a couple of days growth in the summer and even eventually pull buildings and structures apart left alone for a few years.)
Good luck. Remember, you WANTED a wisteria bonsai. They're a pain in the ass all the time, except when (And If) they bloom...
A house in North Carolina where things got out of hand.