Please, forgive me if it seems quirky when I suggest that bright, merry, and yummy seasonal items make good compost. I've been composting since 1984, but my composting education continues . . . learn more by clicking the link above.
My grandma knew something about weeds that too many have forgotten: Hot composting is one of the best ways to kill the seeds. Better yet, hot composting does this without making ash, without a trip to the town dump, and without adding methane emissions at a landfill.