Or would I have to wait for the winter like other trees? I’m thinking about doing some work on an Italian cypress, which is slow growing.

The general rule for every tree is repot in spring when buds start to open.
But, there is a tendency nowadays to repot in high summer ( august), especially for pines. But it all comes down to your skill level, experience, tree health, etc. So, again, repot in spring to be safe.

No.

If you mean a standard repot, like root pruning and such... no.. don't do it, unless you really know what you are doing.

if you want to up-pot... i.e. move the tree from it's current pot into a larger pot without disturbing the roots... that can be done.

If I were to up-pot, would I need to use the same medium or could I switch to another potting mix or akadama?

No need to use the same mix.

Tropfrog wrote: No need to use the same mix.

So I could even switch completely to akadama? Akadama is a medium but not soil per se.

remember with an up-pot the most you're doing is loosening up the roots on the side of the root ball, and putting it in a larger container. You're not changing the soil in the root ball at all. It might be difficult with watering longer term if you only use akadama. That all depends on your climate etc.

Wes V. wrote:

Tropfrog wrote: No need to use the same mix.

So I could even switch completely to akadama? Akadama is a medium but not soil per se.

Switch completelly to akadama is not the right time of the year. I thought we were discussing uppotting. Uppotting means to plant the entire root ball and old soil into a bigger pot and fill up with new soil/substrate.

Tropfrog wrote:

Wes V. wrote:

Tropfrog wrote: No need to use the same mix.

So I could even switch completely to akadama? Akadama is a medium but not soil per se.

Switch completelly to akadama is not the right time of the year. I thought we were discussing uppotting. Uppotting means to plant the entire root ball and old soil into a bigger pot and fill up with new soil/substrate.

When could I switch to akadama?