I bought a 5 gallon NDM from a local nursery. I am not sure of the root stock. It looked terrible after few weeks. I thought it is going to die. After much reading from this forum, I took the risk on the $85 NDM by removing all of the soil and rinse the root. I then re-potted with with 1/3 sand, 1/3 peat moss, 1/3 perlite with some charcoal and organic fertilizer. For months, it does not do anything. I thought I am kissing my $$ goodbye. However, in the last two weeks, the NDM give 3 new growth with about 6" each.
I strongly believe the combined knowledge of the members on this forum is incredible. I will try to replace peat moss with pumice next repotting adventurer.
All my plants I bring home and re-pot have about 1 year lag before they actually grow strongly. My Diamond mango is absolutely FLYING this year and is adding a new branch every week it seems - lots of blooms too, but overall doing a lot of nice growing of leaves. I'm about to swap into the recommended soil mix here. Apparently that stinky stuff has tons of nutrients to it and can feed for a year or something.
Plan is to use:
50% coarse sand
30% gromulch
5% peat moss
15% pumice stone (found a line on it sold as Dry Stall, a "volcanic aggregate for horse stalls" and well recommended by succulent nerds)
1/2c of azomite
mykos soil additive