I always inwardly cringe when they start going off topic and the host keeps trying to rein them in. But when it's someone who knows how to present themselves on

I always inwardly cringe when they start going off topic and the host keeps trying to rein them in. But when it's someone who knows how to present themselves on radio, it's good. There's this one show on CBC where listeners call in to a plant expert about their gardening problems, and he identifies them and suggests solutions on the spot. You get a wide variety of people who call in, but since the roles are reversed—callers are asking questions, not answering them—they tend to be much more to the point and willing to give up the floor. Despite not caring one whit about plants and gardening, I really enjoy this show. If the expert doesn't know the answer, sometimes another listener will call in to save the day. One of my favourite ones is when a lady's tree saplings were starting to die after they got a new well drilled, and after a bunch of questions the plant expert was stumped. Well, a well driller called in a few minutes later and said it was almost certainly the oil coating used on the pipes to prevent rust during storage (totally safe for consumption, but apparently harmful to trees), and the solution was to wait until the oil wore off after a few months. It sounds boring, but the plant expert is one of those old men who just have a way with words, and the CBC host is really good with prompting both the expert and caller with more questions or anecdotes.