Kinda figured my compost bin played a role. Simple, made from 7 heat treated pallets, just 3 bins. toss each bin over to aerate when I dump lawn clippings in bin 1, and every 2-3 months flip each bin to the next. All sorts of kitchen organics go in there, and luckily the bears don’t bother with rotten veggies and egg shells here. By the time it moves from the 3rd bin, its been composing 6-9 months. Generally no weed seeds, and been lucky with the outdoor nasties…
But I rarely top dress, even in the veggie garden. When they are done in pots I will dump all the soil, amend, mix in some new, and go again. Sometimes I dump it on the 3 bin compost bin (I guess recharging it there as well lol)
I am not a fan of MG. Nor chemical ferts. Probably why I’ve been pretty much organic soil mixes my entire time. And why my compost bin is used on all the beds / gardens I have when I plant new things…
Maybe I oughta try top dressing more often 
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