There are always a few in the group, kids who really couldn't care less about the garden, who want to take the sticks that line its edge and swing them at each other, or look at me and whine, "Can we go insiiiiiiiide?" That's when I lean forward and tell them the secret.
"There's a black jelly bean plant," I tell them. "It doesn't have beans, but it smells just like them, and if you find it and smell it, you'll think it's Easter morning again." Their eyes light up (no matter if they actually celebrate Easter or not in their families) and they start to scan the garden. It suddenly looks different to them, like a magic place with hidden treasure, and they start touching and smelling, in search of the jelly bean plant (also know as French tarragon!). Long before they find it, they find the lemon balm or the rosemary or the tangerine sage or, if they are very lucky, the pungently-sweet lemon thyme. They start asking me, "What's this? What's this?" and they share leaves with each other. I ask them if they want to smell the difference between peppermint and spearmint. I ask them if they want to smell pizza (oregano and basil). I point to a stalk and tell them to pull it up and watch their faces as an onion appears.
We don't always make it to the Black Jelly Bean Plant. But one thing is for sure. We never go back insiiiiiiide.