Richy Pots...

The only thing I would really say about the richy pots for parsnips is that you'd need to plant them out before the root touches the bottom.  Or you could get forked roots.

I never sow my parsnips in pots now, only insitu.  Even if they are a bit late, like  they were last year.  I still had loads of lovely parsnips.  Which was nice, as I have had a couple of bad years parsnip wise.

as long as the paper is moist the root will grow straight through. Tear off any pot that is above ground, when planting, otherwise it works like a wick and makes the pot dry out.