A mix that is coarse, porous, durable, well-aerated, free-draining. This means that the particulate needs to be gritty, with most particles in the 1/8 to 1/4 inch range. In zone 9b, you have a bit more leeway in that your warm weather will mitigate some of the issues associated with heavier, more moisture-retentive mixes. Many of us use bark-based mixes that are amended with small fractions of perlite, pumice, turface, potting mix, et cetera. Fafard's "Nursery Mix" is reportedly very good off the shelf. "Orchid Mix" with some tinkering can be decent as well. Most "Citrus mix" is peat-based, however, so you'd want to avoid that...or else heavily amend it with coarse perlite. Josh

gardengal, I can find a lot of information concerning Miracle Grow 24-8-16 but not the 24-8-18 formulation poncirusguy suggested. From your post evidently you must know what range of micros MG 24-8-18 offers, I curious to know, what are they?

The nursery that doctorcopper purchased the trees from did not even grow the trees, they were grown by a wholesaler. I went to MyCitrusTrees.com (whom the nursery purchased the trees from), and looked at the growers fertilizer information. They did not recommend a balanced fertilizer at all, but one higher in nitrogen and potassium. What they recommended was a 18-5-10 slow release fertilizer applied 3 times a season. MyCitrusTrees.Com are actually trees grown by Record Buck Farms. The lady at the nursery that doctorcopper purchased the trees from did not know what she was talking about.

15-3-15 will be fine. Don't give it more thought, you have given it too much thought already... If you can find a foliar fert containing trace elements, this will be good if sprayed twice a year in early spring and in autumn. Sometimes these contain also N other times not. Any will be fine. About the 46-5-5, apply that sparingly. Zn is mostly what's missing from it.