I've found some fabulous links here, most of them are not particularly Halloweeny!!!
Living Montessori Now pumpkin themed ideasLiving Montessori Now more pumpkin links...
My Montessori Journey pumpkin ideas
Growing in Peace a link to pumpkin growth sequencing cards
My Montessori Journey, pumpkin drawing
Mommy's Monkeys, pumpkin playdough
Roots and Wings Co, Pumpkin spice Playdough