>>Something happened to MiracleGrow potting mix. It was always my go-to for potting soil. Last year it was full of fairly large wood chips.<<
I had the same experience. And most of the others as well. I went to straight black cow for seed starting since I can't find a potting soil that has no large pieces of bark. It was either that or screening the potting soil.
Like a fool, last April I screened an entire 50 pound bag. And got over 12 pounds of scrap I didn't want for seedlings, especially tiny little tobacco seedlings.
Once. They can only screw me over once. Then they get fired. ;)
/johnny