In a slow cooker, mix poultry seasoning, 1 tsp. salt and 1/2 tsp. pepper. Add pork roast and rub with seasonings to coat. Toss apples and sliced fennel together and put around and underneath meat. Pour in cider. Cover and cook on low until meat is tender and a meat thermometer inserted in center of roast reaches 145ºF, 3 to 5 hours.
Transfer pork, apples and fennel to a serving platter. Carefully pour sauce from slow cooker into a fat separator. Pour skimmed sauce into a small saucepan; discard fat. Bring sauce to a boil over high heat and boil until reduced by half, about 15 minutes. Slice meat, garnish with fennel fronds and serve, with sauce on the side.