I grow around 8 different species of lilium, and they generally grow about 1 inch a day on average until they reach full height. Some of the smaller ones, more like 1/2 inch a day since they only get up to 2-3ft. I think I might get a few 8 footers this year. Here's some of them in my collection.
These are my top performers with 2 stems per plant.
This is just gladiolus. They happened to just start coming up a few days ago and have really proliferated well since last year.