Yellow leaves in my Cilantro Plant

As I was harvesting my Cilantro for some slow cook bean soup, I noticed that the leaves in the lower part were starting to yellow.

I researched the problem and found that yellow leaves in cilantro can mean several things.  Generally when leaves turn yellow in a plant it means that you are overwatering.  However in cilantro, yellow leaves can mean either overwatering or underwatering. When I felt the soil, it felt dry so I decided the problem must be underwatering.  Cilantro is in the parsley family and needs a lot of water in well draining soil.  I have heard that cilantro is very selective about its environment.  In the right conditions it can thrive, but in the wrong conditions there is little you can do to keep it alive.   I am hoping that my balcony provides the right conditions for cilantro.  We will find out.