The following out-of-season wishing customs come from different areas of the same city; interestingly, each uses seeds, but from different plants.
Blow on a dandelion puff (made up of dandelion seeds) and tell Santa Claus what you want for Christmas.
Hold a winged-seed from a maple tree on the palm of your hand and blow it away as you wish for what you want Santa Claus to bring you at Christmas.
(Pittsburgh, Pennsylvania)