I'm looking for the recipe for Al's gritty mix potting soil. Can somebody help me out here?? Thanks.
Equal parts by volume:
Pine or fir bark in 1/8 - 3/8" size (no fines)
Screened Turface MVP
Crushed granite (Gran-I-Grit, in grower size) or #2 cherrystone
Excuse me, please - the gypsum is not part of the 1:1:1 ratio. Include it in the soil @ 2-3 teaspoons/gallon of soil. Sorry.
I typically see your Gritty mix recipe (with gypsum) include the caveat of adding Epsom salt when fertilizing (for Mg) but only once have I seen you say "if you use Foliage Pro 9-6-3, don't add Gypsum or Lime in the original mix at all".
Was this out of context or does FP provide enough of all the Ca,S,Mg nutrients to not use gypsum when originally mixing the gritty mix? I'm only speaking to the gritty mix since I know liming the more organic 511 mix also addresses pH issues.
Would there be any noticeable effects when doing both (having added gypsum at 1tbsp/gal to gritty mix and also using FP in 1/4 of "maintenance dose" at each watering).
I do just that (add gypsum + use FP). I don't know the exact reason WHY, but I have discovered that plants in the gritty mix seem to grow better across the board if I use gypsum when I make the soil, whether I use MG (which lacks both Ca and Mg) or FP, (which includes both). I add the Epsom salts, even when using FP, to keep the Ca:Mg ratio in line so no antagonistic deficiencies develop.
It may be that if you use the gritty mix with only FP and no gypsum, that the starting pH of the gritty mix is low enough that the Ca fraction of the FP remains reactive and largely unavailable. The added gypsum/Ca is probably simply increasing the actual presence of Ca just enough to ensure there are no pH related deficiencies.
Al, sorry if its been mentioned before...but when you say add
2-3tsp of gypsum per 1 gallon potting mix, would that be appx. the size of a 6" pot? How many Cups(appx.) would that be? Just want to add the right amount as much as possible.
There's no way to be exact about the amount of soil in a 6" pot unless you measure it first (fill w/water & measure) or do the math for the volume of a truncated cone. I suppose you'd have to eyeball it & guess, or make the soil in 1 gallon increments & store the leftovers. for the gritty mix, 6 cups of screened Turface, 6 screened bark, and 6 grower grit makes a gallon ..... if that helps at all?
You stumped me. ;o)
What you posted above(6 cups each) makes sense and helps a LOT. I will use that recipe. Sorry Al, didn't mean to stump you,lol...Thanks again!
Maybe it's somewhere on here, but I don't know what to necessarily search for. I am new to plants of any kind and have just received a desert rose and would like to repot it out of the store mix, since it seems to not have enough drainage... anyway, what does "screened" mean? and why do it?