Lots of "reds", Mary.
Though heirloom garlic is fairly easy to grow, at least for me, it has been a learning curve to grow it and I am still learning. Knowing when there is 1/3-1/2 lower leave yellowing is a guess. Some of those leaves may have dropped, so how do you know?
Seeing the softneck and Creole stems collapse/bend is another way to tell that it is time. You have to watch for this.
Hardnecks won't "collapse" though, the stems are too tough.
Mary, and others, I have never seen a pest attack any of my garlic in the last four years that I have seriously grown it. Zero.
Deer and rabbits won't touch it.
Mary, you and so many others in the North will have to tell me what your experiences are. I truthfully don't know how to tell you to grow it. Your feedback will not only help me to tell others what to do and what not to do, but others on OTP.
It you don't plant your garlic in the late-summer/fall (depending on your location), you are in for a disappointment.