Purim/Adar: Rainbow cake not a healthy option? Put a spring into everyone's step by making a rainbow flower wreath out of recycled egg cartons. Prepare them now, and use them to decorate for Passover/Pesach. This also would be a great project for Shavuot.
ballon wreath - use about 300 balloons on straw wreath, leave the plastic wrap on and use greening pins (also called floral pins — they’re sort of U-shaped and can be found in the artificial flower section at craft stores)
Just make paper flowers and glue to old wreath (DI or garage sale find), or even the swimming noodle idea and there you go, a super cute Easter wreath! (Possibly add some colored plastic eggs to add a little something to it)