Parents who homeschool often have their kids engage in programs like the Boy/Girl Scouts (thought I would not let my daughter attend Girl Scouts as it is run by NOW), sports, church activities, and the like so that the kids do socialize with other kids.
My wife (to be) and I are going to try and have kids right after we get married (less than 2 months). She wants to homeschool them until they are old enough for high-school, we both want them to have homecoming games, the prom and all that fun stuff but we also want them not to be indoctrinated eight hours a day by the government while they are very young..
A minimum of 9 months is usually recommended.