if your ordering from the doc, ive never heard of any trouble except with these types of larger orders, u might run into trouble. then again, u might not. if ur package is sent as 1st class mail, then ur chances of getting caught are lower than if it was like a box. USA customs don't use agricultural scanners like they do in australia and new zealand, at least not on a consistent basis. they are insane with their customs because of how their environment can be affected so easily by foreign plants/animals.
if you really want to be sure, you can choose the overnight/immediate delivery option. overnight rush delivery is never checked. ever. u can send a lot of weed this way, i know people around here that get california bud overnight rushed to the east coast and they've been doing this for years (its really expensive though, adds an average of at least 100-150 dollars)