How often do you actually clean your deck?

I’m curious how often other homeowners clean their decks. Do you usually do it once a year, only when it starts looking dirty, or just before summer gatherings?

I’ve noticed that decks can collect a surprising amount of pollen, leaves, dirt, and organic buildup, especially in shaded areas or underneath trees. I’m also wondering whether regular cleaning makes a noticeable difference in how the deck holds up over time.

For those who have hired a professional, what made you decide it was time to call someone instead of handling the cleaning yourself? And were there any particular things you looked for when choosing a local exterior cleaning company?