Wouldn't it be best to study the soil conditions (alongside altitude and climate etc.) Of where c. Sinensis and C. Arabica are native to and try to imitate that? What coordinates/latitude are you at? Elevation?
Mimicking exact indigenous conditions is going to be next to impossible. My hope is to keep all of these plants which aren't hardy up to my zone of 5b growing in pots in the winter, and outside in the summer. I'm trying my best to focus on the aspects of the environment I can actually control such as soil pH/drainage/porosity/water retention, watering schedule, nutrient additives, sunlight hours and intensity, pot size and shape, and to a lesser degree humidity.
I'm opting for 4 1/2" terra cotta pots to start with a more frequent watering schedule as opposed to a less frequent/plastic pot setup. The breathability of terra cotta is very appealing to me. I'll stick with this style pot for now, at least until they're bigger. In which case coffee and tea will get large deeper pots, as they're trees, and blueberries will get shallower wider pots as they like to spread out more.
Coffee likes broken/indirect sunlight and not full sun, as I found out my 2nd year with it when it got a bad sun burn. Both tea and blueberries like bright light, but do best with indirect in the hottest part of the day.
I believe coffee and blueberries' native soil is very humus heavy, though finding pure humus for cheap is next to impossible around here. Hell, I can't even find it locally at all, let alone for a good price. Coco coir or peat could make good substitutes with a higher N value nutrient addition, especially peat which tends to help the acidity be on the low side...
I find the pine bark fines very attractive for a soil component since they are larger and have a 'softness' not unlike vermiculite. It allows very large soil air pockets which are moreso important for the blueberries than the other two.
Does anyone happen to know someone in china? haha