Catherine, Mine are doing the same thing, and we had a really long, cool spring. We are just now getting some HOT weather all of a sudden, and the ground has not really warmed up much. Might be what it is.

Cold spring has little to nothing to do with this. We also had a cold spring here, but my 2 year old Orienpets are about 6 feet tall. I already answered Catherine's question in the identical thread she opened yesterday.

I'm sorry...I am new to the website and inexperienced. I could not find my original posting so therefore I posted a 2nd one. I appreciate your comments.

Catherine, it my fault: I should've posted the link to your first post... I thought that you did not like my answer for some reason... Honestly, I do not think that the cold weather affects the growth of the stems. Despite the extremely cold and late spring, all of my second year Lilies grew according to their genetics. Dwarf varieties stay short. Orienpets are taller than me!
First year Lilies almost always are shorter than mature plants. They have to grow lots of roots to get established. Potted Lilies especially. They are somewhat exhausted from being treated with chemicals.
They will be much taller next year. They will probably reach their mature size in a couple of years.