Sure, I don't mean to be controversial, or recommend what anyone else should do, but just answer the question. I got sick of spending $ on garbage that killed my plants (and turned into a fungus gnat farm) and have been using ground soil out of my garden for the past few yrs, about 3-6 yrs, depending on the specific pot. I wish I would have done this much sooner.
A few of my bigger pots have "cactus & palm" soil just because of the reduced weight. When I spend $, that is what I get. If I could find some, I would use cococoir. I've purchased a few plants in that and it is wonderful stuff, like a million tiny sponges, and not hydrophobic if I lapse in watering for so long that it gets dry.
Some people swear by MG, and more power to them! But I can't get along with peat from any brand. Unglazed clay pots could help, if you want to try to make use of the MG bag you have, because the clay can breathe. And NOT packing soil into a pot. Try to leave it loose and airy, watering very gently the first few times so it doesn't compact. (I don't miss trying to do that either.)
A quote from Al,
If you start with a pint of water-retentive medium and add a particle the size of a BB or a peppercorn. It increases the o/a volume of the medium by the volume of the BB/ peppercorn without increasing aeration, so aeration on a per volume basis decreases. As you continue to add the BB-size particles, even by the hundred, aeration continues to decrease until you've added a volume of BB size particles large enough to ensure there is no longer enough fine material to fill all the spaces between the BB-size particles.
The point at which there is exactly enough fine material to fill all spaces between the coarse particles is called the "threshold proportion", and it is the most difficult combination of the 2 materials to grow in; however, if additional coarse material is added to a mix of materials at a threshold proportion, aeration and drainage begins to increase exponentially. Ideally, you would start with a mix of very coarse material (particles in the 1/10-3/16" size range) and add only enough fine material to ensure you are comfortable with watering intervals, making sure there is nowhere near enough fine material to decimate the medium's potential for aeration and drainage.
He also recommends reading this, more in-depth info with illustrations:
https://www.controlledenvironm...
