I have grown citrus (as bonsai candidates) in the gritty mix and they did very well. I also have figs in it. I also have friends that grow both figs and citrus in it with excellent results, so there would be no issues concerning the use of the gritty mix from a physiological perspective.

You have probably read that the gritty mix is adjustable for water retention, but keep in mind that if you start employing tricks (like not screening the Turface, in order to increase water retention, you give up aeration and eventually you come to the point where you might as well use any old soil from a bag.

By keeping the bark component at 1/3 of the o/a volume & increasing the Turface fraction commensurately with a decrease in the granite, you'll end up with lots of water retention and will still maintain the benefit of much greater aeration than that of a peat-based soil; and, you can count on that aeration for longer than it's prudent to wait between repots.

The figs are extremely vigorous and easy - just bare-root and reduce the roots before budswell and repot.

The citrus, I would saw the bottom 1/2 of the roots off & then remove wedges of soil like pieces of pie from the remaining root mass. In the subsequent spring, do the same thing with the soil you did not remove this year. You might skip the next year and start anew in the third year. That way, you'll be replacing the old soil and pruning roots over 2 years and then skipping a year.

Find more general info here.

Al

garderme: FWIW So far this year, I've bareroot re-potted into gritty mix over a dozen container citrus trees, including oranges, lemons, and mandarins (no limes yet). Nearly all were from the 3.4gal #5 black nursery pots. I haven't lost a tree, and only two showed *any* negative signs whatsoever (likely from a mistake I made) that lasted about a month before improving rapidly.

The majority were done in my hot arid 100 degree heat of summer. Some were done in spring while in full flush, others had fruit, and two were completed in the last three weeks (during winter).

I'm convinced if you're careful and prepared, complete re-pot of citrus trees into the gritty mix dose not pose a significant risk. However, I would not expect much root regrowth to occur if done in these cold winter temps -- so it's best to wait until it's about to warm up.

I did not use the method Al described (about taking pie wedge cuts out) as he has stated that is a conservative, staged approach he recommends when unsure about how well the tree will tolerate the "harsher" approach I took.

Whether to prune the bottom roots or not I cannot address and would certainly defer to his advice.