First off, I'd like to reach out from the community here and welcome you to this forum!

What you are explaining could be many things. If the middle nodes are becoming yellow, that indicates that it isn't a lack of sun that's causing the yellowing. Do you have a pH meter to measure whatever you're giving them?

How many times are you watering/feeding them?

Have you inspected your plants for any bugs?

I wish you the best of luck with your outdoor, I've had some good and bad times with nature.