What is traditionally thrown at a wedding for good luck?

Myffa, Rice is toxic to birds uncooked as it expands in their stomachs and kills them.

Castra, Many churches now insist on rice or biodegradable items. That way pigeons or mice etc clear it up and vergers dont have to sweep it up.

Yana, Confetti is in the UK, even if they dont know why.

The word traditional threw me off. Confetti is not tradition.

Bluemoon7, How would you know that? Rice was not an answer option.

Interesting .., everyone thinks it’s rice.