The Field documentation says:
Setting the status based on field validity is up to you. In the example below, it's done as you're changing the input. You could also validate on blur to give the user a chance to finish filling out the field.
However, it then doesn't provide an example of how to delay validation until blur, and it's not immediately obvious (at least to me) how you would do this. It would be helpful if the documentation included an example of how to do this, so that we can establish a pattern that we want developers to follow when doing validation on blur.