Banana peppers start out yellow and turn red when ripe. Whatever you grew grew was not a banana type. The generic "Banana" is availalable as either a sweet or hot variety. There are several hybrid versions Sweet Spot, Banana Bounty, Pageant, Bananarama. Sounds like a seed source problem.

Farmerdill knows this business.

You can buy Banana pepper seeds at most big box store. I just bought a SWEET variety packet few days ago . Cost -$1.10. Distributed by Ed Hume seed company.

I have planted sweet banana peppers back a fer months ago the plant is producing very large peppers but they are turning yellow. I got these seed from a local store my others plants are doi g good turning those r plants i bought. Any help we have had a lots of rain but i had this plant up against the house so it wouldn't get all the rain.