I dunno for tomatoes specifically because I don’t grow them but there are other considerations at play than growing zone. Plants have wildly different needs for light, moisture, how well the soil drains, soil pH and more. For example blueberries need acidic leaning soil and will die if their soil is too basic since they can’t get nutrients or their soil gets too waterlogged they are attacked by fungus because they’re adapted to well-draining acidic soils. Some plants need fertilization to continue thriving but carnivorous pitcher plants will get burned by the excess nitrogen and will also fare terribly in non-moist soil. I’d assume that, since NM has very hot and dry weather and basic soils, at least one or more of those trips up tomatoes.


Imported types (ex. from the German states) for printing presses didn’t have it because it was an English only letter. Rather than coming up with expensive home modification (which some did anyway eventually but not en masse) there were easy alternatives because use of th was already established and also the letter y kind of looked like thorn in the fonts of the time so you could also sub that in.
Convenience of just doing a workaround rather than paying more money for a more English type modification won out and with so many using th and the thorn disappearing soon the use of the y that looked like thorn dropped out also.