Hi,
This is my first time on this site... Which I must say is very informative in a wide range of topics... Okay my question... Where I live as I take my morning walk are a group or tiger lilies about 4" tall... Is it a good time to dig them up and transplant them to my yard?? ;)

Most certainly. As long as you get only the root and transplant they will flourish for years to come. I have done this many times. I enjoy the orange flowers in my garden.