How often to refill Thistle Socks?

My Thistle Sock isn't being used much anymore,but still looks about 1/2 full.
Could this be just hulls? Do I need to empty it and refill?
Hate to ask dumb question, but that idea just occurred to me today......that perhaps it needed refilling.

Finches are very picky regarding fresh thistle seed (especially Goldfinches). If it has been out in the heat and humidity for about a month, the birds will generally stay away from it. Especially this time of year when there is plenty of fresh alternative growing naturally.

In short, yes. Put new fresh seed in the sock and your finches will come back in flocks.

This message was edited Jun 5, 2009 12:35 PM

The benefit of fresh thistle....