Potted Nagami Kumquat needs new soil
We have a potted Nagami Kumquat (the plant tag says "true dwarf") that we bought several (5-6) years ago. The pot is one of those lightweight foam terra-cotta look-alikes, about 15-20 gallons. The plant is still in the same potting mix since it was planted. I used a good commercial bagged potting mix topped with a layer of small bark mulch. It has gotten monthly (or almost monthly) feedings of E.B. Stone Organics Citrus & Fruit fertilizer (7-3-3) during the growing season.
After a slow start the first 1-2 years, it has done fairly well and produces new fruit each year.
However, the soil line has sunk to at least 6" from the top of the container (see photo below), and it is time to add and freshen up the soil.
I've been reading about Al's famous gritty mix, and I'm convinced it is good stuff. However, I work full time and have had some health issues lately and would prefer not having to drive all over creation to find Turface and some of the other ingredients at this time -- instead, I'd like to use similar ingredients that are easy to find locally or we may already have on hand. I figure that if the plant has produced fruit every year in the same ol' commercial bagged mix, then it will be fine in a fresh mix of ingredients similar to the gritty mix. :-)
We have several bags of Earthgro Natural Mulch (ingredients = "forest products") that we mixed with sphagnum peat and perlite in our Blueberry pots. The mulch has mostly fine particles with a few wood chips and chunks. I'm considering using a similar mix to transplant the Kumquat into the same pot.
1. What ratio of these ingredients should I use? Would 1:1:1 be best?
2. Should we use the same pot, or get a smaller one?
3. Do I need to add anything to green up the leaves, or will the new mix, along with the regular feedings and some liquid seaweed take care of that?
The plant gets full sun in a southern exposure. In spite of our hot summers, I tend to be conservative about watering this pot since it is insulated. Even when I forgot to water in previous hot summers, the soil did not seem too dry.
I would appreciate your suggestions.