Plastiquem: PLOU I TOTS ANEM AMB PARAIGÜES. Crayon and watercolor umbrella drawings. Crayon resist with blue water correct over white crayon. Or cool colors over white crayon and make the umbrella warm colors only.
Fall trees with newsprint trunks. Maybe have kids look up images of trees on computers and discuss how they would change the art project to fit the season. ie What would the bare branches look like in art