Our school begins to work on it in preschool, and gets serious in kindergarten. They want all of the kids to be able to tie their own shoes by the end of kindergarten.
Halfway through the year, only 2 of the 10 in my son's class had it mastered.
My 1st 2 kids could tie their shoes by the time they were 5. Number 3 is taking his time. He's STILL working on it, and he's six! It drives me crazy. To many "slip" on & velcro style shoes. No laces anymore!