You say your kale is good, but how much can you really sell it for per catty? To not mention anything else, in the current market situation, it's barely break-even to transport it out of the county. Sending it out of the province would result in losses so severe you'd cough up blood in frustration.
Choosing kale is even less sensible than choosing Tanghe County's gardenias, since at least those are Chinese medicinal materials and much easier to transport as finished products. The only reason the city chose kale, I reckon, is related to the fact that the county famous for kale is quite impoverished, purely an act of looking after the less developed areas. After all, Tanghe County's economy has already raced ahead in the Wan City region.
But when it comes to provincial evaluations, they're looking at prospects, not giving handouts to lagging areas.