To root down is to ground yourself in the experience of now, to be fully present in the moment. Sometimes the moment is extremely pleasant, like when you wake up everyday in paradise on a yoga retreat. But sometimes that moment is difficult, when life is challenging you to expand and grow. Part of the practice is steadying yourself in a moment of discomfort when it comes, so that your best self rises to the challenge. From that vantage point, one can more easily find a sense of contentment in the present, whatever it may be, recognizing it as the great gift it is.