Can I get back a block I deleted?

Yes, in a click, if you deleted it from a season on: the block waits for you in Growing locations on the Farm Map. Click Restore next to it to bring it back on the season it was deleted from.

Its plantings are not put back on their beds: place them again on the Crop Map. Look at the following seasons too, each may need its own restore. A block deleted across all seasons cannot be brought back.

See Edit, move or remove a location.