Since you have access to Farfard products, look for their Professional Potting mix. Not exactly the same as the gritty mix but one of the closest (and better quality) commercial potting mixes available. And no added ferts - you can keep with the Foliage Pro.

Thanks norwoodn. You motivated me to read up on the 5-1-1 and gritty mix here on gardenweb (there's a lot to read). Ended up repotting with a 5-1-1 based on "micro" bark (the "fines" were pretty chunky at the local garden store). When I went to repot, the old soil was so dense and soggy, a lot of the lower roots just tore off. So I guess that counts as repotting/root pruning. Now I have it recovering in the shade, we'll see if it can rebound.

I would say.. Over watering... As njoasis said, if you don't have a deep root system to be stable enough to stand on it's own, then your roots must not able to handle the about of water you give it. Almost always the first signs of yellowing leaves can be attributed to overwatering, or wet feet, rotting roots not able to take up water, which in effect stunts growth and the ability for the plant to take up nutrients. My brother-in-law used the drip method on his, while all were in more than 8 hours of full sun, and still killed all 6 of his this way... i salvage one for him. I would let nature or hand watering to the job. Roots have to dry to allow exchange of air in soil for roots to breathe. As suggested by many here, let it dry out between waterings, unless of course, you have it planted in a fast well draining mix, such as the gritty mix suggested on the container forums where air exchange occurs generously even after a good watering. I do have one question? You said that it was root bound? Did you break up the roots at all, or did you just plop it into the new mix? Also, if it were me, I would not stick in the hot full day sun if it is in a container for a while, instead it should get just morning and late afternoon sun, or in dabbled light for a bit,to let it rehydrate, rejuvinate, and start to green up again.. I have a couple of citrus that sit under a tree all summer, and are as healthy and as green as could be, with much fruit and flowers..It will still gets lots of light to help it heal, until ready to provide full sun. Sometimes to much sun while the roots are trying to function properly, can and will dehydrate your plant and cause ultimate death in a hurry. Good luck..;-) By the way, Hi njoasis!! Hope you are well..:-)

thanks, dsieber! my issue, however, is space. i know the tree won't die going from zone 9 to 6 in the summer, but i really need to minimize the space my plants are going to take up in my car on moving day! therefore, i was thinking about pruning severely and repotting into a small pot just for moving purposes. any thoughts?