sorry to be so difficult, but I find the czech train and bus schedule very poor compared to de bahn. I would love to see Cesky Krumlov from plzen , but struggle to confirm a specific leave plzen and return from cesky. whew
Looks doable at 3 hours each way with a connection in Ceske Budejovice. It shows up on the DB site as 3 hours each way. One problem I do notice, cd.cz will not show connections to other operators, namely trains marked "Os" regionalzug. I'd say wing it and get round trip tickets to Ceske Budejovice, then round trip to Cesky Krumlov on the Os train. And don't feel like you have to book in advance.
have a look at this website ,it can give you various option of trains, busses or a combination of both.Never travelled from Plzen to Cesky Krumlov but have used that website numerous times for organising trips within the Czech Republic.
Czech train and bus schedule for your purpose is certainly better than de bahn. De Bahn is showing only trains, on Czech site you can get either trains or buses or combination. Use the link Unclegus provided. I did and had no problem to find connections to Cesky Krumlov from Plzen and vice versa. And also could buy the tickets on line which in most cases is not necessary but I would recommend it for Regiojet aka Student Agency. Explain why you struggle. The schedule is very clear.
Hi from Wisconsin,
Go to www.cd.cz. This is the Czechia equivalent of dbahn. Tickets are a fraction of the cost anywhere else. REALLY, like 50% off or more, and you can print the ticket our here at home on conventional paper. I just booked Prague to Brno, about a 2 and half hour ride for 119 CZK, that is under $6 one person, one way.
It allows you to pick the wagon (carriage) and seat, usually no charge.