Totally ignoring the fact in the previous episode the cave people had farms but were too occupied with phones to attend to them, Luigi wants to teach them how to grow crops; Mario isn't supportive, asking why should they do that if they can simply grab some berries from any random bush? The Princess simply says if Luigi wants to give it a try, let him try. So he starts off with showing them how to plough, tying a turtle shell plough to Yoshi's back, but as you'd expect when Yoshi's involved, the sight of a berry sends him running everywhere and unintentionally becoming an artist.
Unknown to them, Bowser and Cheatsy Koopa are spying on their game, planning to pinch their produce so the cave people will have to come to them for food, although they ignore the part after that. Do they eat the cave people or charge them inflated prices? You never know. Bowser just walks away and leaves Cheatsy to take care of things.
Luigi moves onto showing them how to plant seeds, but also ignores the whole seed part of the process, suggesting they can plant anything, resulting in such hilarity as whole apples, a tree and a cave person being planted in soil. "Rats! If they can't grow crops, I'll have nothing to steal!" complains Cheatsy.
The next step, watering the seeds, also fails again because of Luigi's vague instructions. "Go get some water" doesn't specify how much water, what they should store the water in, or anything at all! So you can't really blame the cave people for lifting up the whole well and flooding the field. Mario uses this opportunity to nonchalantly diss his brother, who maintains the thought the crop growing business will turn out good.
And somehow, he's right! Growing a large variety of vegetables with the cave people not being morons for once, Mario finally compliments his work, while Luigi just cracks a gag.
Mario is not amused.
That night, Cheatsy finally has vegetables to vamoose, so with an army of Monty Moles, they pluck them from below and in the morning, and once Mario, Luigi and Yoshi come to check up on things, replace them with potted Piranha Plants! Yoshi saves them from the first one, but after that apparently decides to play along with their "we're doomed" game.
Cheatsy orders his produce pilfering pals to move in, which for whatever reason makes Yoshi into a food critic who comments on everything he eats, and soon munches all but one of the Piranha Plants. It's only then that the moles decide to save it, turning the simple process of eating something into a game of tug-o-war for Yoshi, though he prevails in the end. Mario gives Cheatsy a good ol' fashioned tongue lashing, but doesn't actually get around to doing anything since the bad guys simply escape down the hole again.
They follow after them and Luigi is about to chase after them through the pipe, but Mario actually suggests they let the bad guys win by going back to picking berries. Luigi, however, begins crying and says that he doesn't have any food stored over for the winter, all because of his crop growing idea, and it's all his fault. Mario has a change of heart and agrees with Luigi's plan of getting the crops back, so after announcing "one for all, and all for dinner", they leap into the pipe for some gopher bashing!
Except the pipe leads into a pit of death.
Good thing they found a magic balloon!
They land safely and hide behind a wall of blocks, and spy on the Koopaling complimenting himself on such a devious plan, ultimately leading into a very awkward song time. I admit that watching Cheatsy Koopa sing and dance while his Monty Mole minions sing an opera chorus is indeed interesting, but it kind of made my head explode the first time I saw it.
The good guys' then abduct all of the Monty Moles without Cheatsy noticing, and once he does, he pulls a Tom & Jerry shocked expression not once, but twice. The second time just before he's crushed by his own minions.
Back at the field, Luigi opens the bag of stolen crops and out of it rolls a grossly overweight Yoshi, whose destruction of the vegetables is taken in stride pretty well, but is told to plant them again. He burps in response, and everyone laughs because bodily functions are hilarious. And Peach appears again after having disappeared after the first thirty seconds of the episode.
Luigi cries over the fact he hasn't stored any food for winter, making it sound like it's just round the corner, yet when Yoshi eats all the crops he says "oh no! Now we'll have to plant them all over again!", making it sound like there's no worry at all. Confusion.
Gotta love how the debris of the Monty Mole's piggy bank abruptly vanishes after Cheatsy is done looking through it.
I swear, Luigi has never looked more evil. It's even creepier with his deep, opera singing voice.