Giant Vegetables

[RoyalBlue305]

Hi can someone tell me what the giant vegetables are for? I can't plant them but they're in my barn. If I go to sell them, it gives a warning that they'll all be gone. I'm assuming these were for a past event that I didn't participate in but wondering why there would be a warning if so.

[RoyalBlue305]

I'm now seeing requests for the vegetables in the train delivery. Here's one for the corn. Is there any info on these plants? I don't know where you can plant them. Is there a different plot like the watermelon plots?
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[RoyalBlue305]

Here's another example with Stormie selling a Gourd or Squash.

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