I have two black willows that I rooted from cuttings last summer. They've been growing vigorously since I repotted them in the spring and I now see roots poking out from the bottom of the pot. I've read in some places that (weeping) willows should sometimes be repotted twice a year. The trees look healthy all over and have had pretty explosive growth. It's the end of July in southeast Pennsylvania. Should I trim the roots and repot?

TheSwanOfEndlessTales wrote: Should I trim the roots and repot?

Not yet.
IF I were you, I would...
Wait for next spring, and then you will have a pretty good idea of how fast they are root-bound or not.
And if they really need to be repotted twice a year.