If your college savings portfolio tanks in the fall of freshman year, you won't have the luxury of waiting for it to rebound. That's why a college portfolio should become tamer as the student gets closer to matriculating. The idea is to protect the gains instead of angling for more.
To rein in the portfolio, shift assets into a short-term bond fund. If the markets turn ugly, the bond fund won't lose much--if any at all.
Start moving some of the portfolio's assets seven years before you need to make that first tuition payment. That should cushion you against a prolonged market slump.
In fact, at that seven-year point, your child's college education isn't a long-term goal; it's an intermediate-term goal. As such, the portfolio should begin to look more like an intermediate-term portfolio than a long-term portfolio.
To learn how to craft an intermediate-term portfolio, review Portfolio 209: How to Invest for Intermediate-Term Goals.