Almanzo and Laura's neice Jenny loses some motor function and speech abilities because of a swimming accident that deprives her brain of oxygen. A retired Doctor (Dr. Marvin) helps her regain her spirit and health.
Marvin's Garden seems almost dead-on typical of the later seasons of the Little House series, a nice self-contained story, but with some problems that might annoy long-time fans.
The story itself has a nice message, one of how feeling useful in some way is very important to the health of the human condition -- for Doctor Marvin himself, his friend who makes the Doctor flower boxes, and for Jenny's recovery. As usual for Little House, this episode shows nice relationships between characters of different generations.
What is annoying are some of the details of the story as they pertain to the series. This is the second time in one season that Jenny nearly drowns and is rescued by Jeb Carter. And who Doctor Marvin is seems a mystery to followers of the show. He still has a license to practice (he loses it because of encrouching blindness in this episode). He surely would have come in handy during the many medical crisis's that struck Walnut Grove and the surrounding Hiro Township over the years. If you count the missing-in-action Dr. Ladoux from the previous season, it seems like three doctors would have been available to the rural community. None of this is deadly to the episode as a stand-alone experience, but just a few words of explanation of the Doctor's history (since he and Dr. Baker speak to each other often in this episode) would do wonders. Details like this seemed to escape the writers many times by the end of the Little House series.