When are posts searchable on Tumblr?

[Some]

I started my first account, but my tagged posts don't show up in the search results when I search the tags. I heard that new accounts must wait a certain amount of time for their posts to start to be searchable, to minimize spam. Any input?

[BJG]

I have no idea about new blogs having to wait, but if you're just typing it into the search bar, try changing the settings on the left to 'most recent' instead of 'top posts.'