brining turkey in the planter

SFGate's brining recipe:

* 1 turkey, about 12 pounds
* The brine:
* 1 cup sugar
* 1 1/2 to 1 3/4 cups kosher salt
* 2 1/2 gallons cold water
* 2 bay leaves, torn into pieces
* 1 bunch fresh thyme
* 1 head of garlic, cloves separated and peeled
* 5 whole allspice berries, crushed
* 4 juniper berries, smashed (see Note)
* For roasting:
* 2 tablespoons softened butter + butter for basting
* 1 1/2 teaspoons freshly ground black pepper
* 1 cup chicken stock, or more as needed