Combine all of the spices in a small bowl and set aside.
Cut the head off the garlic head and lay this and the lemon wedges from the lemons in bottom of slow cooker.
Remove insides from chicken, rinse chicken and pat dry. Season chicken well, inside and out, with the seasoning mixture.
Lay chicken on top of garlic and lemon slices.
Cover crockpot and cook on high for about 4 hours or on low for 7 hours, or until chicken reaches 165 degrees. (Slow cooker cooking times vary, so use a meat thermometer to check for doneness.)
When chicken has reached 165 degrees or higher, turn off slow cooker and let chicken rest for about 15 minutes.
Remove from slow cooker, carve and enjoy!