Those plants are WAY too big for those pots.
Get them in 3 gallon pots of nice LIGHT soil with plenty of extra perlite. A mix of 2-3 sacks MG organic choice plus 1 sack perlite is okay if home depot is your only option, but look at garden centers for other types of potting soils.
Don't use pots that have built-in drip trays. In fact, drill EXTRA drain holes.
The yellow low leaves are probably a combination of N deficiency or lockout from not enough fertilizer and /or not enough root space (I'm voting for root space), and not enough light.
I'll stick this over in problems and merge them.