Repotting

Here is a shot of my dormant Adenia glauca. Its big at around 12in diameter. I want to repot it and would like some input from some experienced people. I am sure I have overpotted it in the past and have just used commercial potting mix - basically peat moss.
What would be a better mix? I have learned since joining DG that peat moss is not the thing to use. I have gotten Coir, crushed gravel and pumice and have it on hand.
What size pot? Bigger? Same size?
Should I wash off the old medium from the roots or leave the root ball alone and put new stuff around it?
Thanks in advance.
Helen

Adenias, when growing, like more water---so I'd get a commercial cactus soil mix and use it straight---you don't need to cut it with anything. I would also get a pot only about 1-2 " larger in diameter that the one it's in. Your plant is in the house---did it drop it's leaves this winter and go into dormancy?

Yes it goes into dormancy every winter. It drops all it leaves and a lot of the vining stems dry up too. I only splash some water on it about once a month. In the summer it grows and flowers all season. Then I give a fair amount of water and full sun, though I do try and protect the caudex from direct sun.
What do you think about the old potting medium its in? Should I leave the root ball intact or try and rinse the old stuff away?
Thanks.

Helenchild, the plant seems healthy and happy with the care it is receiving and the soil it is in, BUT, leaving the old root ball and surrounding it with a different medium might create a water circulation barrier between the two differing soils. I would wash off the old soil (while it is dormant) if the plant were mine. Don

Thanks Don. Your suggestion is what I had in mind. But I did want to run it past experience people since all my knowledge is self taught. DG has been great for me to ask others and learn new and better techniques.

Helenchild, you might want to wait for more input as I am not the most experienced person on this forum. There are others with many years more experience than I have. Don

Generally, when repotting, I loosen up the old root ball---I don't wash it off. Just make sure the soil is loose and the roots are loose and not circling the root ball. This way there is no tight root ball barrier to prevent the roots from growing into the new soil. Adding drainage material keeps the soil light and slows down compaction.

I thought I would update this thread. I repotted the plant. Most of the old soil came off but I didn't wash it. The roots weren't crowded and looked great.
I made a mix of a peatless organic stuff, coir and lots of pumice and crushed granite(bird grit). I also used a smaller round clay pot.
As you can see from the picture I must have hit the right combo of conditions. It has been growing and blooming like crazy.
Thanks again for your input.
Helen

Helen, what a nice fatty! I only have a tiny seedling germinated a couple of years back.

Regards,

Martin