What I tell prospective parents when they call asking if their child is old enough.
Often I get parents calling and asking what age their child should start riding. So what is the "magic" age for riding horses? Like most of life, there is no one answer. Like horses, humans are all unique, with strength and weaknesses that have nothing to do with their age. The key, I believe, is to have reasonable expectations of progress.
While my literature says I give lessons to children six and older, I am far from hard line on this. I have started lessons for children as young as three. My daughter rode her pony almost daily from just before she turned two. There are some things parents need to be very clear about.
1) The lesson price is the same because I almost always spend just as much time with the child however the I will follow the child's lead regarding how much time they spend on the horse. We play games and make it fun, but there is only so much a three years old can do and if they want to be done, they're done.
2) There will be things they should not learn yet. Motor skills are still developing and some things they would have to learn "wrong" to compensate for this.
3) They still may develop some "bad habits" for the above reason. They will have to "unlearn" those later on.
4) An eight year old that starts at three will probably not be that far ahead of an eight year old that starts at three
5) If they LOVE it, it's worth it. There are motor skill that can be learned more quickly by children who are enjoying what they do and feeling accomplishment from taking care of and riding. It is a great teaching tool and they learn much more than just how to ride. (I continue to be amazed at the number of adults that don't realize that to unbuckle a halter one must not hold the strap up against the buckle)
6) Some children would be better waiting until they are six, or even eight. If they are very prone to frustration or impatient with themselves, waiting is better.
The best course of action is to discuss the goals and concerns and be willing to reevaluate if it looks as though the child is not enjoying themselves. It is hard for a parent to hear that the child is not ready but it's more important that the children learn that horse riding is FUN!