Why do you want to start chess lesson as early as possible?

When some parents visited me for evaluation, they would naturally ask for class time. I mentioned one time, they would say "that's not good for us, because our kid has another activity", or "we will travel for a month.​" They will look for a perfect time to start the chess lesson for their child. But sometimes this perfect time never comes.

How many times do you see a child does his homework without taking a lesson? Almost none. If you don't let him take a lesson, he will not do any related work, unless it's purely play. Chess is not pure play. Chess is play and work. 

If he doesn't take lesson, doesn't do homework, will he go to tournaments? I can bet he doesn't even know where to find a tournament. 

If he doesn't play in tournaments, how long can his interest last? From my experience, the longest might be 2 to 3 years, while the shortest is just a few months. When his interest is gone, he will slowly stop playing chess. When he grows older, he might realize, what a beautiful activity he has missed.

All these are starting from a chess lesson. So don't procrastinate. You never know your child's potential. He will surprise you again and again. You might have next Magnus at home.