Can I delete a crop?

Yes, a crop your farm created, with Delete crop; Heirloom’s own crops stay in the library, ready for another season. Deleting your crop also removes its plantings and its charts, so check its Plantings tab first.

To clear one of Heirloom’s crops from your season, take its bookmark off in the Crop Library and delete its plantings.

The steps are in Create or edit a crop.