What adaptogens are and aren’t, how they work, and why we love them—though not more than any other classification of herbs, of course—is the single most common topic I’ve been asked to speak about in my career as an herbalist. To be an adaptogen, a substance must be nontoxic in therapeutic doses, nonspecific, and systemically normalizing. The ingredients must also work through the sympathetic nervous system and hypothalamic-pituitary-adrenal (HPA) axis—the sort of master-control system that regulates the body’s response to stress, comprised of the hypothalamus, pituitary gland, and adrenal glands. Adaptogens also coordinate the release of hormones such as cortisol to mobilize energy reserves and enable us to adapt to stressors.

I notice winter first when the leaves begin to dry, fade, and fall. I imagine the life force of the tree receding back into its trunk and underground roots. I feel a bit melancholic at first—not wanting to have to follow nature’s lead in hunkering down and going in. But I’ve come to love Fall as a season as full as any other, with its own flavors, rhythms, and herbal remedies.